Caveman
2011-09-22, 17:01
3 Step Overclocking Guide – Bloomfield and Gulftown
Introduction
So many users are searching around the net these days looking for advice on how to overclock their new systems but don’t know where to start. *To help everyone out, I decided a how-to guide was in order. *Searching around forums can be confusing and intimidating. *There are so many people willing to give advice, but who can you trust? *It’s hard to know, and I’ve seen many users sent on wild goose chases because they are following advice that doesn’t solve or even address their specific problem. I’ve also seen too much trial and error overclocking, unless you get lucky it tends to be far too time consuming a frustrating. What I’ve attempted to do is create a very simple three step guide for overclocking Bloomfield and Gulftown based CPUs. *If you want to continue searching out other opinions, please consider each suggestion with caution. Some will undoubtedly be great, some will not.
Disclaimer
I am not responsible for any bad things that happen to you or your computer as a result of you following this guide, nor is oldguys.eu. *My goal is for this guide to be a safe overclocking guideline, but the burden for damaged hardware lies on the user performing the overclock! *Overclocking can damage hardware and in most cases will void your warranties.
Prerequisites
In an earlier version of this guide, I requested that you have some basic knowledge of your motherboards BIOS. *While I have not addressed every motherboard on the market, I have included details for the top enthusiast brands. *But as before, please do not be afraid to get into your BIOS and have a look around, if you are ever concerned that you may have changed a setting erroneously, you can always load defaults, and start over. *Most boards have a CMOS reset button on them now-a-days, if not check your user manual for the location of the CMOS reset jumper…please ensure you know the location before getting started.
This guide is independent of your cooling system. *Whether you are using the stock Intel cooler or if you’re pushing to the extreme with phase change cooling, the basic steps remain the same. *One thing that is far too common are mistakes mounting your cooling system, specifically the application of the thermal interface material (TIM). *If you don’t have much experience mounting cooling apparatus, please refer to this excellent guide from Arctic Silver.
Methodology
Determining methods for finding a stable overclock are highly controversial, everyone has their own definition of a stable system, but when I refer to “stable” in this guide, I am referring to the stability of your selected “stability test.” *So for a power user or gamer who wants a reliable system that won’t ever crash due to an overclock pushed too far, you’d need to test with a program that will load all of the cores and threads applicable to your CPU, OCCT and IntelBurnTest are two popular choices. *OCCT uses the same algorithm as Prime95 but has a more friendly interface. *IntelBurnTest uses the Intel linpak binaries to stress the system and also has an easy to use interface. *In this guide I may use testing this is insufficient in your opinion. *It is only a guidline and if you feel more testing is necessary for your system, by all means feel free.
So with that in mind, we will attempt to isolate each portion of the system and overclock one step at a time. *This may seem time consuming at first glance, but rest assured this will potentially save you hours of troubleshooting and frustration. So go slow, and follow each step very carefully.
BIOS familiarization
If you’ve found my guide online, my guess is you’re looking for more than a basic overclock. *If you’re not, and all you’d like is something simple, please redirect your attention to your motherboard manufacturer’s website and download the latest overclocking utility. *For basic 10-20% overclocking, they work pretty well. *There is “Gigabyte EasyTune6“, “Asus TurboV EVO“, “MSI Control Center“, and “eVGA eleet“. *This guide is written to take it to the next level, for THAT we need to do the overclocking from the BIOS.
Speaking of which, before we begin, please check your motherboard manufacturer’s website for the latest version of your BIOS. *Usually enthusiast level boards will have BIOS engineers tweaking them for months or years to improve overclocking support. *Unless you have a reason to stay with your current BIOS, I’d update to the newest version.
If you don’t know how to access the BIOS, please refer to your motherboard’s owner’s manual for instruction. *While you’re there, find out how to “clear CMOS”. *As I mentioned in the introduction to this guide, it’s important you know how to properly “clear CMOS” before we begin.
Secondly, the first thing to do after powering up the new system is to enter the BIOS and find the “hardware monitor” area and verify the CPU temperature is reasonable based on your cooling. *If not, please power down the system and verify the mounting of your cooling apparatus (refer to the guide linked in the “prerequisites” section above).
Goals
The variety of users reading this guide is vast, and each user’s goal will be unique and specific to his/her needs. *It would be impossible for me to address every user’s specific needs. *But I’ve attempted to be as broad, yet specific as possible. *My goal is to assist the maximum number of users as possible, despite your specific needs.
Based on user feedback from the previous version of this guide, I decided to better address overclocking with power features enabled. *The easy answer was to follow the old guide and then attempt to enable your power features afterward, but that rarely worked when approaching the limits of a given system.
Just as before, if you want to maximize your overclock, you should disable all the power saving features in the BIOS as detailed in step 1. *However, if you’re after a more moderate overclock, and you’d like to save power (especially while your system sits idle) you can leave those setting enabled. *Just follow the guide as written (I’ve added tips for you along the way) to find your best settings. *While your potential overclock will be more limited, the bennefit will likely be worth it to many of you.
Terminology
I’d like to start off by writing briefly about the BIOS and more specifically, differences in terminology between the different manufacturers. *Obviously there are too many motherboards on the market to show you every single one in this guide. *But looking at boards from the four top manufactures, we should be able to better identify specific terminologies used by each.
Below I’ve created a table comparing the terminology used by the four major enthusiast motherboard manufacturers.
http://www.mngeu.com/download/images/Bloomfield_terminology.jpg
***A brief note about Asus. *Asus makes multipliers a little more confusing in this guide because the BIOS doesn’t show the ratios at all, they only show the speed of the item based on the bclock set. *This requires a little additional math on your part while using this guide. *Please be aware of this difference as you progress***
Throughout this guide, I’ll be referring to the terminology used by Gigabyte because it is most familiar to me. *This top section is to be used for reference so that you know what I’m referring to you when your BIOS options don’t match my instructions.
Understanding “total system performance”
Before we go into how we overclock these CPU’s let us look at what determines how fast your whole system will run. *CPU frequency is very important. *However, there are many other factors that play into your total system performance. *All of your primary BIOS overclocking revolves around the Base Clock or “bclock” and multipliers. *The base clock’s default speed for all X58 based systems is 133MHz. *Typically we shoot for an overclock in the range of 200MHz bclock….but doing that has a major effect on a number of things…
CPU frequency = bclock x CPU clock ratio
This is a biggest change from the old LGA 775 where FSB and multiplier determined the CPU speed. *The base clock is similar to the FSB but also has some key differences. *The bclock is the basis for all the other frequencies discussed below. *So as you increase bclock, you’re affecting the speed of many components.
The CPU speed is the primary concern for day to day, noticeable performance gains, but not the only factor that determines how fast your PC will run.
QPI frequency = bclock x QPI clock ratio
QPI or Quick Path Interconnect is the Intel communication path between the CPU and the X58 chipset on the motherboard. *So all devices not controlled on the CPU die itself have to communicate with the CPU via the QPI. *For instance, the memory controller in built into the CPU, so the memory bandwidth is not limited by the QPI, it has it’s own direct link to the CPU. *However, the PCIe controller is located on the X58 chipset, all of your storage devices, NICs, audio devices, USB devices, etc….they all have to communicate with the CPU via the QPI.
The good news here is that Intel created the QPI for CPU to CPU communications for use in multi CPU servers for the enterprise market. *That means the bandwidth they built in is HUGE, and in reference to overclocking, higher QPI speeds don’t affect performance enough to notice in day to day activities. *So I never run the QPI clock ratio beyond x36, with the bclock at 200MHz this would result in the QPI running at 7.2GHz which is plenty for anything you might throw at it.
Uncore frequency = bclock x uncore clock ratio
Uncore is everything on the die that is not “core”, primarily, the memory controller and the L3 cache. *It’s important to note that the L3 cache performance can have a major performance impact in many applications. *If you’re trying to get very high overclocks on your memory or if you are running large quantities of memory, or if you have all six slots utilized, you may need to compensate by giving the memory controller extra juice, ant that would be done in the form of VTT voltage.
Bloomfield require the uncore frequency to be, at a minimum, double that of the DDR speed. *So if you are trying to get your memory to run at DDR3-2000, you’ll need to have your uncore running at 4000MHz minimum.
With Gulftown based CPU’s the requirement is only x1.5 the DDR speed. *For instance, if you want to run your memory at DDR3-2000, then you’ll need to have your uncore running at 3000MHz minimum.
Memory frequency = bclock x System Memory Multiplier (SPD)
Memory is shown in the BIOS as a multiplier of 6, 8, 10, etc… *This represents the multiplier to reach the DDR speed. *So, a stock 133MHz bclock with the multiplier of 8 would result in a memory speed of DDR3-1066.
DDR – The other part that can be quite confusing for users who are not familiar with DDR technology is the difference between the memory clock speed and the memory’s DDR speed. *For instance, DDR3-1600 actually runs at 800MHz, it’s just that DDR (or dual data rate) technology allows the memory to process twice per clock cycle. *Back when we switched technologies from SDRAM to DDR for the first time, the manufacturers started saying DDR-400 when it ran at 200MHz because it was better marketing to sell their memory over the older SDRAM technology. *This is why CPU-Z shows 800MHz for your DDR3-1600, or 1000MHz for your DDR3-2000.
Memory speed and bandwidth can have a huge effect in some applications, and negligible impact on others. *But overall, top shelf memory is one of the worse items you can spend your money on from a value perspective. *Faster CPUs and GPUs will give you much more performance for your hard earned cash.
Important Voltages when Overclocking
There a few important voltages which you will need to manipulate while overclocking, below are the main ones. *Not every motherboard BIOS is identical, but all enthusiast level motherboards should provide control of the voltages as shown below.
CPU Vcore – Directly related to the CPU frequency. As you increase the CPU frequency you would need incrementally increase the v-core as well. *Bloomfield has proven to be extremely durable and I ran a number of Bloomfield CPU’s through the gauntlet and back with very high vcore. *Everyone continues to ask what is “safe”, and I’ll continue my previous suggestion that a safe voltage for you system should be determined by your LOADED CPU core temperatures. *So, while you are stress testing, monitor your CPU core temperatures with Real Temp and if the temperature is under control, you can SAFELY increase the voltage. *So, the next logical question is what is a safe temperature, and Intel says 100C, and that’s what I go by.
Nothing I’ve ever used my computer for come close to generating heat like IntelBurnTest configured to use all threads. *Because it generates so much heat, it has become my favorite stress testing application. *As long as I can keep my CPU cores below 100C while running IntelBurnTest, then for me that’s safe. *If you are more conservative/cautious than me that’s perfectly OK. *IntelBurnTest at default will only spawn one thread for each physical core, so if you have HyperThreading support enabled on your CPU, please manuall select the number of threads in the drop-down box corrosponding to your CPUs thread count. *From this point forward I will use the terminology IntelBurnTest (maximum) to remind you to manually configure the thread count if your CPU has HyperThreading enabled.
QPI/VTT voltage – This is the uncore voltage. *Remember that the primary uncore devices are the L3 cache and the memory controller. *This is also the primary adjustment required to increase bclock frequency. *Again, for Bloomfield I personally wouldn’t hesitate to run mine up to about 1.45V on air 24/7. *For Gulftown I don’t like to go over 1.4V for daily use.
DRAM voltage – This is directly related to your RAM modules and increases will allow increase in MEM speeds. *There has been a lot of debate as to the limitation 1.65V limitation Intel has published. *For quite a while users have been running much higher DRAM voltage without ill effect. *The justification has always been that the default VTT is 1.15V and the DRAM voltage has to stay within 0.5V of the VTT. *I have always played by that rule, although many power users have questioned whether it’s needed or not. *Doesn’t really matter to me, because I usually run VTT at 1.3V minimum which would allow me to run DRAM voltage up to 1.8V without breaking the rule, and 1.8V is plenty for most memory on the market these days.
Whether or not it’s necessary I’m not going to debate here, but it’s an easy rule to follow, and it’s stood the test of time that you can safely run your DRAM voltage up to VTT +0.5V
Sample overclocking goals to use as a reference
I keep going back and forth with this guide trying to make it easy to read for everyone, and yet still relevant to anyone’s personal goal. *Sometimes as I’m typing away, I feel like I’m over explaining things over and over and that it’ll cause more confusion than clarity. *So, for clarity, as you read the guide, I’ll be referring to the following thee sample goals and hopefully that’ll allow my explanations to be a little more concise.
1.1. Sample #1 – Easy/budget OC – Intel Core i7 920, DDR3-1333 CAS7 1.Bclock freq goal = 180MHz
2.CPU freq goal = 3.6GHz
3.Memory speed goal = DDR3-1440 (uncore @ 2880MHz)
***This OC should be possible with the stock Intel cooler and minimal voltage increases***
1.2. Sample #2 – Moderate/midrange OC – Intel Core i7 930, DDR3-2000 CAS9 1.Bclock freq goal = 200MHz
2.CPU freq goal = 4.2GHz
3.Memory speed goal = DDR3-2000 (uncore @ 4000MHz)
***This OC will require high end air cooling at a minimum and moderate voltage increases***
1.3. Sample #3 – Hardcore/high end OC – Intel Core i7 970, DDR3-2400 CAS9 1.Bclock freq goal = 200MHz
2.CPU freq goal = 4.6GHz
3.Memory speed goal = DDR3-2400 (uncore @ 3600MHz)
***This OC may require water cooling or better and moderate to high voltage increases***
Step 1) *Maximize Bclock & uncore Frequency
I would start by entering the BIOS and select “load optimized defaults”, then save and exit. *After the reboot, go back into the BIOS and turn off the start-up slash screen, so that you can view your system’s post behavior. *Also, feel free to disable any “integrated peripherals” that will not be used (i.e. NICs, extra PATA/SATA controllers, legacy devices, etc). *All other overclocking settings you can leave on auto for now.
If you are looking for your maximum overclock, and you’re not concerned with power consumption, disable all power saving features. *These include, but are not limited to; EIST, C1E, and all other C-states.
Isolate the bclock from the CPU
First you need to isolate the bclock, because all other major devices derive their frequencies from the bclock, it’s the logical starting point. *In order to isolate the bclock from the other components, the first thing you need to do is manually force a low multiplier for the CPU.
•Sample #1, #2, and #3 – set the CPU clock ratio to x15
Isolate the bclock from the memory
Just like the CPU, the memory receives its clock from the bclock via a multiplier, in this case the default is 8 (133×8 = DDR3-1066). *This is expressed in the BIOS as “8?. *For now, we want to drop that down a bit.
•Sample #1, #2, and #3 – set the memory to 6
In all sample system, the IMC is the limiting factor, and we don’t want to push it up yet, that is the reason for all three to be set at 6 for this step, don’t worry it won’t be there for long.
Lock in your desired uncore clock ratio
As previously mentioned, the uncore clock ratio must be set to double the System Memory Multiplier (SPD) with Bloomfield and 1.5 times the memory multiplier with Gulftown. *In this step, set the uncore clock ratio based on your desired System Memory Multiplier (SPD) (not the temporary memory multiplier we’re using right now).
•Sample #1 – set the uncore clock ratio to x16
•Sample #2 – set the uncore clock ratio to x20
•Sample #3 – set the uncore clock ratio to x18
bclock voltages
For this step, there are only two voltages you should play with; VTT, and IOH Core. *IOH Core voltage is easy, if you are running a single PCIe card (graphics card), give the IOH Core 1.1V, two graphics cards 1.15V, three graphics cards 1.2V, or four graphics cards 1.25V. *If you plan to run bclock frequencies far beyond 200MHz, sometimes it may help for the IOH core to be even higher.
As mentioned above, QPI/VTT is the crucial voltage adjustment for achieving high bclock stability. *Default QPI/VTT is 1.15V and to reach 200MHz bclock you’ll likely need to increase this to at least 1.2V, many CPUs will require 1.3V or more. *The only way to know is to follow the instructions here and find out.
For all three sample systems, start by setting the QPI/VTT voltage to 1.2V.
First overclock!
Go into the BIOS and set the CPU Clock Ratio, the Uncore Clock Ratio, and the System Memory Multiplier (SPD) to the setting we just decided on in the previous sections. *Then go to the voltages section and adjust your IOH Core and your QPI/VTT voltages. *Then restart your machine and go back into the BIOS, if your system fails to post, start a new thread in the forums and ask for some specific help. *Please be sure to include as many details as possible when posting in the forums, and post a picture of the specific problem if possible.
After you’ve restarted your system with your manually configured voltages and returned to the BIOS, adjust the bclock speed from 133MHz to 150MHz. *Then save and exit and allow the system to reboot. *This time, allow the system to boot fully into the operating system.
Testing for highest stable bclock frequency
Once the operating system has fully loaded, start up RealTemp. *RealTemp should always be running while checking for stability of an overclocked system to ensure you do not overheat your CPU. *RealTemp shows your CPU’s core temperatures real-time. *Now start up CPU-Z, this utility will allow you to ensure that your overclocked settings have been properly applied, and that you are running at your desired speed. *Check both the CPU tab for the expected CPU frequency, and check the memory tab to ensure your memory and uncore are both running at the appropriate speed. *At this point the sample systems should each show up in CPU-Z with the following speeds.
•Sample #1 – CPU = 2250MHz, uncore = 2400MHz, memory = 450MHz
•Sample #2 – CPU = 2250MHz, uncore = 3000MHz, memory = 450MHz
•Sample #3 – CPU = 2250MHz, uncore = 2700MHz, memory = 450MHz
***Note***, if you have SpeedStep (“EIST”) enabled, the CPU speed will fluctuate in CPU-Z when the load changes, please verify values given above WHILE RUNNING YOUR STRESS TEST.
Now start up your selected test program, for example OCCT (mix) or IntelBurnTest (maximum). *Run the test for just a short amount of time, I usually try to run 3 loops with IntelBurnTest (maximum). *Then reboot the system and return to the BIOS.
1.If the test ran without error, raise the bclock by 10MHz, reboot into your OS and run the test again.
2.If the test failed, raise the QPI/VTT voltage by 0.025V, reboot into your OS and run the test again.
Continue to repeat this testing following the two procedures above, until you meet one of the following three criteria:
•You reach the same bclock speed you identified in step one and successfully pass your stability test.
•You reach your maximum safe QPI/VTT voltage (as identified above)
•Raising the QPI/VTT voltage is ineffective in stabilizing the system.
* Note – there is a phenomena known as “bclock holes” that may create confusion and frustration during this process. *But if you appear to have found your limit at a much lower speed than anticipated, please consider trying a step or two higher before continuing on. *A bclock hole cause’s system instability within particular bclock ranges, and going past them may allow you to regain stability.
Fine tuning
After you have met one of the criteria above, you should have a rough idea of your bclock limit, now it’s time to get a little more fine tuned. *So, revert back to the highest speed THAT PASSED the stress test. *Then continue the same procedure as before, but instead of 10MHz bclock changes, shift to 2MHz changes until you meet one of the three criteria again. *Also, ensure you check my note about “bclock holes” above, the same concept can be applied to this fine tuning step as well.
After you have found your highest stable speed to within 2MHz accuracy, lower the bclock by 2MHz and run your test again. *This time let the test run for a full hour. *If it passes the test *- Congratulations! – you have found your highest reasonably stable bclock frequency. *If it does not pass, drop the bclock 2MHz and attempt the full hour long test again, continue to lower the bclock in 2MHz increments until the one hour test will pass.
For the purpose of this guide, I’m going to assume you met the goal as provided in one of the 3 sample systems listed above.
Step 2) Optimize Memory Frequency & Uncore
System Memory Multiplier (SPD)
The next step is to find the limit of your memory. *In order to do this, we need to prepare you to meet your memory overclocking goal. *Start off this step be entering the BIOS and setting the bclock frequency back to 150MHz. *Because we have already been through the range of bclocks from 150MHz to 200MHz (or whatever YOU reached), we already know that the bclock and uncore will be stable with these settings. *So that effectively allows you to go back through the same range again, changing only the variable of memory, so that you’ll KNOW that that any instability is memory related.
To do that you need to change your System Memory Multiplier (SPD) to a ratio that will allow you to push the blcock back up to your goal, whichout exceeding the memory’s rated speed. *Also, manually configure the memory timings according to the manufacturer’s specifications. *There will probably be many sub-timings in your BIOS that you could change, but only change the timings specified by the manufacturer, the others leave on auto.
Lets look at the sample systems for an example, for those systems you would configure the System Memory Multiplier (SPD) as follows.
•Sample #1 – set the System Memory Multiplier (SPD) to 8
•Sample #2 – set the System Memory Multiplier (SPD) to 10
•Sample #3 – set the System Memory Multiplier (SPD) to 12
For the sample system #1, the goal is 180MHz bclock, the multiplier is 8, and the memory is rated at DDR3-1333. *If we were successful in reaching the 180MHz bclock goal, the memory would be at 180×8 = DDR3-1440. *This is about an 8% OC and within the 10% I recommend limiting yourself to for this step.
For the sample system #2, the goal is 200MHz bclock, the multiplier is 10, and the memory is rated at DDR3-2000. *If we were successful in reaching the 200MHz bclock goal, the memory would be at 200×10 = DDR3-2000. *This is the memory’s rated speed and within the 10% I recommend limiting yourself to for this step.
For the sample system #3, the goal is 200MHz bclock, the multiplier is 12, and the memory is rated at DDR3-2400. *If we were successful in reaching the 200MHz bclock goal, the memory would be at 200×12 = DDR3-2400. *This is the memory’s rated speed and within the 10% I recommend limiting yourself to for this step.
In the same way, set your multiplier according to your goal, so as to prevent more than a 10% overclock on your memory. *As a generalization, memory rated at lower speeds typically has more overclocking potential than higher rated memory. *My suggestion for now is to focus on getting the IMC overclocked to the memory’s rated speed (cause remember, the IMC is only rated to run at DDR3-1066).
Instead of overclocking memory, I place a higher value on tightening up timings. *Take sample #2 from above, it has DDR3-2000 CAS9 memory. *You’ll get better day-to-day performance out of that memory by tightening the timings down to CAS8 level, as opposed to overclocking the speed to DDR3-2100…..not only that, but tightening the timings is almost always easier than increasing the speed. *Again, I’m not going to get into detail here because tangible differences on a daily system will not exist.
DRAM voltages
There are two voltages we need to focus on in this section, the QPI/VTT voltage you’ve already become familiar with, and the DRAM voltage itself. *QPI/VTT is already high enough to support your bclock and uncore goals, but as we push up the speed of the IMC (which is also part of the uncore), the QPI/VTT voltage may need a bit more. *This is especially true if you are running with all 6 memory slots populated, or if you’re using newer 4GB DIMMs, these configurations can put a lot of added stress on the IMC and require extra QPI/VTT voltage to retain stability. *For all three sample systems, set the DRAM voltage manually to 1.65V (or 1.66V if 1.65V is not possible).
Testing for highest stable memory frequency
Now start up your selected test program, for example OCCT (RAM) or IntelBurnTest (maximum). *Run the test for just a short amount of time, I usually try to run 3 loops with IntelBurnTest (maximum). *Then reboot the system and return to the BIOS.
1.If the test ran without error, raise the bclock by 10MHz, reboot into your OS and run the test again.
2.If the test failed, raise the QPI/VTT voltage by 0.0125V, reboot into your OS and run the test again.
Continue to repeat this testing following the two procedures above, until you meet one of the following three criteria:
•You reach the same bclock speed you identified in step one and successfully pass your stability test.
•You reach your maximum safe QPI/VTT voltage (as identified above)
•Raising the QPI/VTT voltage is ineffective in stabilizing the system.
Just as you did in step one, if needed you can follow the same procedure for fine tuning here.
After you have reached your desired goal, be sure to test the overclock with another one hour pass of your selected stability test to ensure the entire uncore is happy with the current configuration. *However, I would add one additional stability test at this point, memtest86+. *IntelBurnTest and OCCT (RAM) are both very good at identifying IMC and memory error, but neither are as strenuous testing the DRAM modules as memtest. *It’s a good way to verify that the memory modules are not defective, and will operate without error. *Run at least one pass, or for 1 hour, whichever is greater.
Congratulations! - You now have a relatively stable bclock frequency and memory frequency.
Step 3) *Stabilize CPU Frequency
Almost there
The last step in this guide is often the first step for users who run into problems and then troubleshoot for days afterward. *Leaving it to the last step makes the task much simpler. *You now have the following settings locked in; QPI/VTT voltage, IOH Core voltage, memory voltage, QPI clock ratio, memory ratio, and memory timings. *That means when we are looking for our highest CPU frequency, there are only two variables we need to play with: bclock and CPU voltage.
Please start by entering the BIOS and adjust the bclock back down to 150MHz, then adjust the CPU clock ratio as follows.
•Sample #1 – set the CPU clock ratio to x20
•Sample #2 – set the CPU clock ratio to x21
•Sample #3 – set the CPU clock ratio to x23
Load-line calibration (“LLC”)
This actually goes by a few different names, but they are all meant as a means to reduce or prevent v-droop. *It does typically ease the overclocking process at the cost of violating Intel’s design specs. *However, overclocking in its essence violates Intel’s design specs, so you’re not breaking any new ground with this feature. *I highly recommend enabling this feature. *High end Gigabyte motherboards have two settings, select “Level 2”. *For more insight on the theory of LLC, refer to this excellent explanation at anandtech.com. *There was also some real world testing recently; feel free to check out Bobnova’s LLC investigation here.
CPU Vcore
That brings us to the first thing that most users want to play with after powering up their new system for the first time: CPU voltage, aka “Vcore”. *As you can see, this is actually one of the last things you should be changing. *I would recommend starting at a nice and easy 1.2V. *Surprisingly enough, many users are able to achieve very good overclocks with this modest amount of CPU voltage. *I would be surprised if sample #1 needed any more than that, sample #2 probably need a bit more, and sample #3 will probably need quite a bit more.
If you are overclocking with power saving features enabled, Gigabyte motherboards will allow you to set the CPU voltage via “Dynamic Vcore” which improves overclocking capabilities while using your power saving features….to unlock this feature; first you have to set the standard Vcore setting to “normal”. *Then set the “Dynamic Vcore” setting to +0.05 and increase as directed below.
Testing for your highest stable CPU frequency
Once the operating system has fully loaded, start up RealTemp. *Now start up CPU-Z and verify that your overclocked settings have been properly applied, and that you are running at your desired CPU, bclock, and memory frequencies. *Each of the sample systems should look like this.
•Sample #1 – CPU = 3000MHz, uncore = 2400MHz, memory = 600MHz
•Sample #2 – CPU = 3150MHz, uncore = 3000MHz, memory = 750MHz
•Sample #3 – CPU = 3450MHz, uncore = 2700MHz, memory = 900MHz
***Note***, if you have SpeedStep (“EIST”) enabled, the CPU speed will fluctuate in CPU-Z and the load changes, please verify values given above WHILE RUNNING YOUR STRESS STEST.
Now start up your selected test program, for example OCCT (CPU) or IntelBurnTest (maximum). *Run the test for just a short amount of time, I usually try to run 3 loops with IntelBurnTest (maximum). *Then reboot the system and return to the BIOS.
1.If the test ran without error, raise the bclock by 10MHz, reboot into your OS and run the test again.
2.If the test failed, raise the CPU Vcore voltage by 0.025V, reboot into your OS and run the test again.
Continue to repeat this testing following the two procedures above, until you meet one of the following three criteria:
•You reach the same bclock speed you identified in step one and successfully pass your stability test.
•You reach your maximum safe Vcore (as identified above), or maximum safe temperature.
•Raising the Vcore is ineffective in stabilizing the system.
Just as you did in step one, if needed you can follow the same procedure for fine tuning here.
Is it stable?
So, once you find your highest CPU frequency by meeting one of the criteria above, and run OCCT (mix) or IntelBurnTest (maximum) for one hour minimum. *I’d like to refer to all this testing as “reasonably stability”. *In my experience, the true test of stability is the regular daily operation of your system, doing what you intended it to do.
The reason we use testing programs like OCCT or IntelBurnTest is to simulate a worst case scenario. *I have never seen any real world application come close to generating the heat that IntelBurnTest (maximum) generates. *But there are a few that can come close to OCCT, like folding or crunching for distributed computing projects, encoding high definition videos, or very heavy multitasking. *But even though OCCT or IntelBurnTest (maximum) stress tests tend to generate more heat, they do not always find 100% of instabilities. In my opinion, the ultimate test is to use the system!
Final Words
Well, that about wraps it up. *Believe me, there is so much more to overclocking. *There are SO MANY settings you can continue to fiddle with, you may have a million questions at this point about all of the settings in the BIOS that we never touched. *They’re valid questions, but not meant for this guide. *My goal was for this guide to get you 95% of the way in 5% off the time. *Hopefully you’re there! *The other settings in your BIOS will be needed to get you to 100%….but if I included those things in this guide, it would be 3 times as long, and much more complicated.
Please feel free to comment, and post any questions. We will do our best to help you out with any problems you may encounter!
This tutorial is made by Jeremiah Allen and found on http://www.techreaction.net
Introduction
So many users are searching around the net these days looking for advice on how to overclock their new systems but don’t know where to start. *To help everyone out, I decided a how-to guide was in order. *Searching around forums can be confusing and intimidating. *There are so many people willing to give advice, but who can you trust? *It’s hard to know, and I’ve seen many users sent on wild goose chases because they are following advice that doesn’t solve or even address their specific problem. I’ve also seen too much trial and error overclocking, unless you get lucky it tends to be far too time consuming a frustrating. What I’ve attempted to do is create a very simple three step guide for overclocking Bloomfield and Gulftown based CPUs. *If you want to continue searching out other opinions, please consider each suggestion with caution. Some will undoubtedly be great, some will not.
Disclaimer
I am not responsible for any bad things that happen to you or your computer as a result of you following this guide, nor is oldguys.eu. *My goal is for this guide to be a safe overclocking guideline, but the burden for damaged hardware lies on the user performing the overclock! *Overclocking can damage hardware and in most cases will void your warranties.
Prerequisites
In an earlier version of this guide, I requested that you have some basic knowledge of your motherboards BIOS. *While I have not addressed every motherboard on the market, I have included details for the top enthusiast brands. *But as before, please do not be afraid to get into your BIOS and have a look around, if you are ever concerned that you may have changed a setting erroneously, you can always load defaults, and start over. *Most boards have a CMOS reset button on them now-a-days, if not check your user manual for the location of the CMOS reset jumper…please ensure you know the location before getting started.
This guide is independent of your cooling system. *Whether you are using the stock Intel cooler or if you’re pushing to the extreme with phase change cooling, the basic steps remain the same. *One thing that is far too common are mistakes mounting your cooling system, specifically the application of the thermal interface material (TIM). *If you don’t have much experience mounting cooling apparatus, please refer to this excellent guide from Arctic Silver.
Methodology
Determining methods for finding a stable overclock are highly controversial, everyone has their own definition of a stable system, but when I refer to “stable” in this guide, I am referring to the stability of your selected “stability test.” *So for a power user or gamer who wants a reliable system that won’t ever crash due to an overclock pushed too far, you’d need to test with a program that will load all of the cores and threads applicable to your CPU, OCCT and IntelBurnTest are two popular choices. *OCCT uses the same algorithm as Prime95 but has a more friendly interface. *IntelBurnTest uses the Intel linpak binaries to stress the system and also has an easy to use interface. *In this guide I may use testing this is insufficient in your opinion. *It is only a guidline and if you feel more testing is necessary for your system, by all means feel free.
So with that in mind, we will attempt to isolate each portion of the system and overclock one step at a time. *This may seem time consuming at first glance, but rest assured this will potentially save you hours of troubleshooting and frustration. So go slow, and follow each step very carefully.
BIOS familiarization
If you’ve found my guide online, my guess is you’re looking for more than a basic overclock. *If you’re not, and all you’d like is something simple, please redirect your attention to your motherboard manufacturer’s website and download the latest overclocking utility. *For basic 10-20% overclocking, they work pretty well. *There is “Gigabyte EasyTune6“, “Asus TurboV EVO“, “MSI Control Center“, and “eVGA eleet“. *This guide is written to take it to the next level, for THAT we need to do the overclocking from the BIOS.
Speaking of which, before we begin, please check your motherboard manufacturer’s website for the latest version of your BIOS. *Usually enthusiast level boards will have BIOS engineers tweaking them for months or years to improve overclocking support. *Unless you have a reason to stay with your current BIOS, I’d update to the newest version.
If you don’t know how to access the BIOS, please refer to your motherboard’s owner’s manual for instruction. *While you’re there, find out how to “clear CMOS”. *As I mentioned in the introduction to this guide, it’s important you know how to properly “clear CMOS” before we begin.
Secondly, the first thing to do after powering up the new system is to enter the BIOS and find the “hardware monitor” area and verify the CPU temperature is reasonable based on your cooling. *If not, please power down the system and verify the mounting of your cooling apparatus (refer to the guide linked in the “prerequisites” section above).
Goals
The variety of users reading this guide is vast, and each user’s goal will be unique and specific to his/her needs. *It would be impossible for me to address every user’s specific needs. *But I’ve attempted to be as broad, yet specific as possible. *My goal is to assist the maximum number of users as possible, despite your specific needs.
Based on user feedback from the previous version of this guide, I decided to better address overclocking with power features enabled. *The easy answer was to follow the old guide and then attempt to enable your power features afterward, but that rarely worked when approaching the limits of a given system.
Just as before, if you want to maximize your overclock, you should disable all the power saving features in the BIOS as detailed in step 1. *However, if you’re after a more moderate overclock, and you’d like to save power (especially while your system sits idle) you can leave those setting enabled. *Just follow the guide as written (I’ve added tips for you along the way) to find your best settings. *While your potential overclock will be more limited, the bennefit will likely be worth it to many of you.
Terminology
I’d like to start off by writing briefly about the BIOS and more specifically, differences in terminology between the different manufacturers. *Obviously there are too many motherboards on the market to show you every single one in this guide. *But looking at boards from the four top manufactures, we should be able to better identify specific terminologies used by each.
Below I’ve created a table comparing the terminology used by the four major enthusiast motherboard manufacturers.
http://www.mngeu.com/download/images/Bloomfield_terminology.jpg
***A brief note about Asus. *Asus makes multipliers a little more confusing in this guide because the BIOS doesn’t show the ratios at all, they only show the speed of the item based on the bclock set. *This requires a little additional math on your part while using this guide. *Please be aware of this difference as you progress***
Throughout this guide, I’ll be referring to the terminology used by Gigabyte because it is most familiar to me. *This top section is to be used for reference so that you know what I’m referring to you when your BIOS options don’t match my instructions.
Understanding “total system performance”
Before we go into how we overclock these CPU’s let us look at what determines how fast your whole system will run. *CPU frequency is very important. *However, there are many other factors that play into your total system performance. *All of your primary BIOS overclocking revolves around the Base Clock or “bclock” and multipliers. *The base clock’s default speed for all X58 based systems is 133MHz. *Typically we shoot for an overclock in the range of 200MHz bclock….but doing that has a major effect on a number of things…
CPU frequency = bclock x CPU clock ratio
This is a biggest change from the old LGA 775 where FSB and multiplier determined the CPU speed. *The base clock is similar to the FSB but also has some key differences. *The bclock is the basis for all the other frequencies discussed below. *So as you increase bclock, you’re affecting the speed of many components.
The CPU speed is the primary concern for day to day, noticeable performance gains, but not the only factor that determines how fast your PC will run.
QPI frequency = bclock x QPI clock ratio
QPI or Quick Path Interconnect is the Intel communication path between the CPU and the X58 chipset on the motherboard. *So all devices not controlled on the CPU die itself have to communicate with the CPU via the QPI. *For instance, the memory controller in built into the CPU, so the memory bandwidth is not limited by the QPI, it has it’s own direct link to the CPU. *However, the PCIe controller is located on the X58 chipset, all of your storage devices, NICs, audio devices, USB devices, etc….they all have to communicate with the CPU via the QPI.
The good news here is that Intel created the QPI for CPU to CPU communications for use in multi CPU servers for the enterprise market. *That means the bandwidth they built in is HUGE, and in reference to overclocking, higher QPI speeds don’t affect performance enough to notice in day to day activities. *So I never run the QPI clock ratio beyond x36, with the bclock at 200MHz this would result in the QPI running at 7.2GHz which is plenty for anything you might throw at it.
Uncore frequency = bclock x uncore clock ratio
Uncore is everything on the die that is not “core”, primarily, the memory controller and the L3 cache. *It’s important to note that the L3 cache performance can have a major performance impact in many applications. *If you’re trying to get very high overclocks on your memory or if you are running large quantities of memory, or if you have all six slots utilized, you may need to compensate by giving the memory controller extra juice, ant that would be done in the form of VTT voltage.
Bloomfield require the uncore frequency to be, at a minimum, double that of the DDR speed. *So if you are trying to get your memory to run at DDR3-2000, you’ll need to have your uncore running at 4000MHz minimum.
With Gulftown based CPU’s the requirement is only x1.5 the DDR speed. *For instance, if you want to run your memory at DDR3-2000, then you’ll need to have your uncore running at 3000MHz minimum.
Memory frequency = bclock x System Memory Multiplier (SPD)
Memory is shown in the BIOS as a multiplier of 6, 8, 10, etc… *This represents the multiplier to reach the DDR speed. *So, a stock 133MHz bclock with the multiplier of 8 would result in a memory speed of DDR3-1066.
DDR – The other part that can be quite confusing for users who are not familiar with DDR technology is the difference between the memory clock speed and the memory’s DDR speed. *For instance, DDR3-1600 actually runs at 800MHz, it’s just that DDR (or dual data rate) technology allows the memory to process twice per clock cycle. *Back when we switched technologies from SDRAM to DDR for the first time, the manufacturers started saying DDR-400 when it ran at 200MHz because it was better marketing to sell their memory over the older SDRAM technology. *This is why CPU-Z shows 800MHz for your DDR3-1600, or 1000MHz for your DDR3-2000.
Memory speed and bandwidth can have a huge effect in some applications, and negligible impact on others. *But overall, top shelf memory is one of the worse items you can spend your money on from a value perspective. *Faster CPUs and GPUs will give you much more performance for your hard earned cash.
Important Voltages when Overclocking
There a few important voltages which you will need to manipulate while overclocking, below are the main ones. *Not every motherboard BIOS is identical, but all enthusiast level motherboards should provide control of the voltages as shown below.
CPU Vcore – Directly related to the CPU frequency. As you increase the CPU frequency you would need incrementally increase the v-core as well. *Bloomfield has proven to be extremely durable and I ran a number of Bloomfield CPU’s through the gauntlet and back with very high vcore. *Everyone continues to ask what is “safe”, and I’ll continue my previous suggestion that a safe voltage for you system should be determined by your LOADED CPU core temperatures. *So, while you are stress testing, monitor your CPU core temperatures with Real Temp and if the temperature is under control, you can SAFELY increase the voltage. *So, the next logical question is what is a safe temperature, and Intel says 100C, and that’s what I go by.
Nothing I’ve ever used my computer for come close to generating heat like IntelBurnTest configured to use all threads. *Because it generates so much heat, it has become my favorite stress testing application. *As long as I can keep my CPU cores below 100C while running IntelBurnTest, then for me that’s safe. *If you are more conservative/cautious than me that’s perfectly OK. *IntelBurnTest at default will only spawn one thread for each physical core, so if you have HyperThreading support enabled on your CPU, please manuall select the number of threads in the drop-down box corrosponding to your CPUs thread count. *From this point forward I will use the terminology IntelBurnTest (maximum) to remind you to manually configure the thread count if your CPU has HyperThreading enabled.
QPI/VTT voltage – This is the uncore voltage. *Remember that the primary uncore devices are the L3 cache and the memory controller. *This is also the primary adjustment required to increase bclock frequency. *Again, for Bloomfield I personally wouldn’t hesitate to run mine up to about 1.45V on air 24/7. *For Gulftown I don’t like to go over 1.4V for daily use.
DRAM voltage – This is directly related to your RAM modules and increases will allow increase in MEM speeds. *There has been a lot of debate as to the limitation 1.65V limitation Intel has published. *For quite a while users have been running much higher DRAM voltage without ill effect. *The justification has always been that the default VTT is 1.15V and the DRAM voltage has to stay within 0.5V of the VTT. *I have always played by that rule, although many power users have questioned whether it’s needed or not. *Doesn’t really matter to me, because I usually run VTT at 1.3V minimum which would allow me to run DRAM voltage up to 1.8V without breaking the rule, and 1.8V is plenty for most memory on the market these days.
Whether or not it’s necessary I’m not going to debate here, but it’s an easy rule to follow, and it’s stood the test of time that you can safely run your DRAM voltage up to VTT +0.5V
Sample overclocking goals to use as a reference
I keep going back and forth with this guide trying to make it easy to read for everyone, and yet still relevant to anyone’s personal goal. *Sometimes as I’m typing away, I feel like I’m over explaining things over and over and that it’ll cause more confusion than clarity. *So, for clarity, as you read the guide, I’ll be referring to the following thee sample goals and hopefully that’ll allow my explanations to be a little more concise.
1.1. Sample #1 – Easy/budget OC – Intel Core i7 920, DDR3-1333 CAS7 1.Bclock freq goal = 180MHz
2.CPU freq goal = 3.6GHz
3.Memory speed goal = DDR3-1440 (uncore @ 2880MHz)
***This OC should be possible with the stock Intel cooler and minimal voltage increases***
1.2. Sample #2 – Moderate/midrange OC – Intel Core i7 930, DDR3-2000 CAS9 1.Bclock freq goal = 200MHz
2.CPU freq goal = 4.2GHz
3.Memory speed goal = DDR3-2000 (uncore @ 4000MHz)
***This OC will require high end air cooling at a minimum and moderate voltage increases***
1.3. Sample #3 – Hardcore/high end OC – Intel Core i7 970, DDR3-2400 CAS9 1.Bclock freq goal = 200MHz
2.CPU freq goal = 4.6GHz
3.Memory speed goal = DDR3-2400 (uncore @ 3600MHz)
***This OC may require water cooling or better and moderate to high voltage increases***
Step 1) *Maximize Bclock & uncore Frequency
I would start by entering the BIOS and select “load optimized defaults”, then save and exit. *After the reboot, go back into the BIOS and turn off the start-up slash screen, so that you can view your system’s post behavior. *Also, feel free to disable any “integrated peripherals” that will not be used (i.e. NICs, extra PATA/SATA controllers, legacy devices, etc). *All other overclocking settings you can leave on auto for now.
If you are looking for your maximum overclock, and you’re not concerned with power consumption, disable all power saving features. *These include, but are not limited to; EIST, C1E, and all other C-states.
Isolate the bclock from the CPU
First you need to isolate the bclock, because all other major devices derive their frequencies from the bclock, it’s the logical starting point. *In order to isolate the bclock from the other components, the first thing you need to do is manually force a low multiplier for the CPU.
•Sample #1, #2, and #3 – set the CPU clock ratio to x15
Isolate the bclock from the memory
Just like the CPU, the memory receives its clock from the bclock via a multiplier, in this case the default is 8 (133×8 = DDR3-1066). *This is expressed in the BIOS as “8?. *For now, we want to drop that down a bit.
•Sample #1, #2, and #3 – set the memory to 6
In all sample system, the IMC is the limiting factor, and we don’t want to push it up yet, that is the reason for all three to be set at 6 for this step, don’t worry it won’t be there for long.
Lock in your desired uncore clock ratio
As previously mentioned, the uncore clock ratio must be set to double the System Memory Multiplier (SPD) with Bloomfield and 1.5 times the memory multiplier with Gulftown. *In this step, set the uncore clock ratio based on your desired System Memory Multiplier (SPD) (not the temporary memory multiplier we’re using right now).
•Sample #1 – set the uncore clock ratio to x16
•Sample #2 – set the uncore clock ratio to x20
•Sample #3 – set the uncore clock ratio to x18
bclock voltages
For this step, there are only two voltages you should play with; VTT, and IOH Core. *IOH Core voltage is easy, if you are running a single PCIe card (graphics card), give the IOH Core 1.1V, two graphics cards 1.15V, three graphics cards 1.2V, or four graphics cards 1.25V. *If you plan to run bclock frequencies far beyond 200MHz, sometimes it may help for the IOH core to be even higher.
As mentioned above, QPI/VTT is the crucial voltage adjustment for achieving high bclock stability. *Default QPI/VTT is 1.15V and to reach 200MHz bclock you’ll likely need to increase this to at least 1.2V, many CPUs will require 1.3V or more. *The only way to know is to follow the instructions here and find out.
For all three sample systems, start by setting the QPI/VTT voltage to 1.2V.
First overclock!
Go into the BIOS and set the CPU Clock Ratio, the Uncore Clock Ratio, and the System Memory Multiplier (SPD) to the setting we just decided on in the previous sections. *Then go to the voltages section and adjust your IOH Core and your QPI/VTT voltages. *Then restart your machine and go back into the BIOS, if your system fails to post, start a new thread in the forums and ask for some specific help. *Please be sure to include as many details as possible when posting in the forums, and post a picture of the specific problem if possible.
After you’ve restarted your system with your manually configured voltages and returned to the BIOS, adjust the bclock speed from 133MHz to 150MHz. *Then save and exit and allow the system to reboot. *This time, allow the system to boot fully into the operating system.
Testing for highest stable bclock frequency
Once the operating system has fully loaded, start up RealTemp. *RealTemp should always be running while checking for stability of an overclocked system to ensure you do not overheat your CPU. *RealTemp shows your CPU’s core temperatures real-time. *Now start up CPU-Z, this utility will allow you to ensure that your overclocked settings have been properly applied, and that you are running at your desired speed. *Check both the CPU tab for the expected CPU frequency, and check the memory tab to ensure your memory and uncore are both running at the appropriate speed. *At this point the sample systems should each show up in CPU-Z with the following speeds.
•Sample #1 – CPU = 2250MHz, uncore = 2400MHz, memory = 450MHz
•Sample #2 – CPU = 2250MHz, uncore = 3000MHz, memory = 450MHz
•Sample #3 – CPU = 2250MHz, uncore = 2700MHz, memory = 450MHz
***Note***, if you have SpeedStep (“EIST”) enabled, the CPU speed will fluctuate in CPU-Z when the load changes, please verify values given above WHILE RUNNING YOUR STRESS TEST.
Now start up your selected test program, for example OCCT (mix) or IntelBurnTest (maximum). *Run the test for just a short amount of time, I usually try to run 3 loops with IntelBurnTest (maximum). *Then reboot the system and return to the BIOS.
1.If the test ran without error, raise the bclock by 10MHz, reboot into your OS and run the test again.
2.If the test failed, raise the QPI/VTT voltage by 0.025V, reboot into your OS and run the test again.
Continue to repeat this testing following the two procedures above, until you meet one of the following three criteria:
•You reach the same bclock speed you identified in step one and successfully pass your stability test.
•You reach your maximum safe QPI/VTT voltage (as identified above)
•Raising the QPI/VTT voltage is ineffective in stabilizing the system.
* Note – there is a phenomena known as “bclock holes” that may create confusion and frustration during this process. *But if you appear to have found your limit at a much lower speed than anticipated, please consider trying a step or two higher before continuing on. *A bclock hole cause’s system instability within particular bclock ranges, and going past them may allow you to regain stability.
Fine tuning
After you have met one of the criteria above, you should have a rough idea of your bclock limit, now it’s time to get a little more fine tuned. *So, revert back to the highest speed THAT PASSED the stress test. *Then continue the same procedure as before, but instead of 10MHz bclock changes, shift to 2MHz changes until you meet one of the three criteria again. *Also, ensure you check my note about “bclock holes” above, the same concept can be applied to this fine tuning step as well.
After you have found your highest stable speed to within 2MHz accuracy, lower the bclock by 2MHz and run your test again. *This time let the test run for a full hour. *If it passes the test *- Congratulations! – you have found your highest reasonably stable bclock frequency. *If it does not pass, drop the bclock 2MHz and attempt the full hour long test again, continue to lower the bclock in 2MHz increments until the one hour test will pass.
For the purpose of this guide, I’m going to assume you met the goal as provided in one of the 3 sample systems listed above.
Step 2) Optimize Memory Frequency & Uncore
System Memory Multiplier (SPD)
The next step is to find the limit of your memory. *In order to do this, we need to prepare you to meet your memory overclocking goal. *Start off this step be entering the BIOS and setting the bclock frequency back to 150MHz. *Because we have already been through the range of bclocks from 150MHz to 200MHz (or whatever YOU reached), we already know that the bclock and uncore will be stable with these settings. *So that effectively allows you to go back through the same range again, changing only the variable of memory, so that you’ll KNOW that that any instability is memory related.
To do that you need to change your System Memory Multiplier (SPD) to a ratio that will allow you to push the blcock back up to your goal, whichout exceeding the memory’s rated speed. *Also, manually configure the memory timings according to the manufacturer’s specifications. *There will probably be many sub-timings in your BIOS that you could change, but only change the timings specified by the manufacturer, the others leave on auto.
Lets look at the sample systems for an example, for those systems you would configure the System Memory Multiplier (SPD) as follows.
•Sample #1 – set the System Memory Multiplier (SPD) to 8
•Sample #2 – set the System Memory Multiplier (SPD) to 10
•Sample #3 – set the System Memory Multiplier (SPD) to 12
For the sample system #1, the goal is 180MHz bclock, the multiplier is 8, and the memory is rated at DDR3-1333. *If we were successful in reaching the 180MHz bclock goal, the memory would be at 180×8 = DDR3-1440. *This is about an 8% OC and within the 10% I recommend limiting yourself to for this step.
For the sample system #2, the goal is 200MHz bclock, the multiplier is 10, and the memory is rated at DDR3-2000. *If we were successful in reaching the 200MHz bclock goal, the memory would be at 200×10 = DDR3-2000. *This is the memory’s rated speed and within the 10% I recommend limiting yourself to for this step.
For the sample system #3, the goal is 200MHz bclock, the multiplier is 12, and the memory is rated at DDR3-2400. *If we were successful in reaching the 200MHz bclock goal, the memory would be at 200×12 = DDR3-2400. *This is the memory’s rated speed and within the 10% I recommend limiting yourself to for this step.
In the same way, set your multiplier according to your goal, so as to prevent more than a 10% overclock on your memory. *As a generalization, memory rated at lower speeds typically has more overclocking potential than higher rated memory. *My suggestion for now is to focus on getting the IMC overclocked to the memory’s rated speed (cause remember, the IMC is only rated to run at DDR3-1066).
Instead of overclocking memory, I place a higher value on tightening up timings. *Take sample #2 from above, it has DDR3-2000 CAS9 memory. *You’ll get better day-to-day performance out of that memory by tightening the timings down to CAS8 level, as opposed to overclocking the speed to DDR3-2100…..not only that, but tightening the timings is almost always easier than increasing the speed. *Again, I’m not going to get into detail here because tangible differences on a daily system will not exist.
DRAM voltages
There are two voltages we need to focus on in this section, the QPI/VTT voltage you’ve already become familiar with, and the DRAM voltage itself. *QPI/VTT is already high enough to support your bclock and uncore goals, but as we push up the speed of the IMC (which is also part of the uncore), the QPI/VTT voltage may need a bit more. *This is especially true if you are running with all 6 memory slots populated, or if you’re using newer 4GB DIMMs, these configurations can put a lot of added stress on the IMC and require extra QPI/VTT voltage to retain stability. *For all three sample systems, set the DRAM voltage manually to 1.65V (or 1.66V if 1.65V is not possible).
Testing for highest stable memory frequency
Now start up your selected test program, for example OCCT (RAM) or IntelBurnTest (maximum). *Run the test for just a short amount of time, I usually try to run 3 loops with IntelBurnTest (maximum). *Then reboot the system and return to the BIOS.
1.If the test ran without error, raise the bclock by 10MHz, reboot into your OS and run the test again.
2.If the test failed, raise the QPI/VTT voltage by 0.0125V, reboot into your OS and run the test again.
Continue to repeat this testing following the two procedures above, until you meet one of the following three criteria:
•You reach the same bclock speed you identified in step one and successfully pass your stability test.
•You reach your maximum safe QPI/VTT voltage (as identified above)
•Raising the QPI/VTT voltage is ineffective in stabilizing the system.
Just as you did in step one, if needed you can follow the same procedure for fine tuning here.
After you have reached your desired goal, be sure to test the overclock with another one hour pass of your selected stability test to ensure the entire uncore is happy with the current configuration. *However, I would add one additional stability test at this point, memtest86+. *IntelBurnTest and OCCT (RAM) are both very good at identifying IMC and memory error, but neither are as strenuous testing the DRAM modules as memtest. *It’s a good way to verify that the memory modules are not defective, and will operate without error. *Run at least one pass, or for 1 hour, whichever is greater.
Congratulations! - You now have a relatively stable bclock frequency and memory frequency.
Step 3) *Stabilize CPU Frequency
Almost there
The last step in this guide is often the first step for users who run into problems and then troubleshoot for days afterward. *Leaving it to the last step makes the task much simpler. *You now have the following settings locked in; QPI/VTT voltage, IOH Core voltage, memory voltage, QPI clock ratio, memory ratio, and memory timings. *That means when we are looking for our highest CPU frequency, there are only two variables we need to play with: bclock and CPU voltage.
Please start by entering the BIOS and adjust the bclock back down to 150MHz, then adjust the CPU clock ratio as follows.
•Sample #1 – set the CPU clock ratio to x20
•Sample #2 – set the CPU clock ratio to x21
•Sample #3 – set the CPU clock ratio to x23
Load-line calibration (“LLC”)
This actually goes by a few different names, but they are all meant as a means to reduce or prevent v-droop. *It does typically ease the overclocking process at the cost of violating Intel’s design specs. *However, overclocking in its essence violates Intel’s design specs, so you’re not breaking any new ground with this feature. *I highly recommend enabling this feature. *High end Gigabyte motherboards have two settings, select “Level 2”. *For more insight on the theory of LLC, refer to this excellent explanation at anandtech.com. *There was also some real world testing recently; feel free to check out Bobnova’s LLC investigation here.
CPU Vcore
That brings us to the first thing that most users want to play with after powering up their new system for the first time: CPU voltage, aka “Vcore”. *As you can see, this is actually one of the last things you should be changing. *I would recommend starting at a nice and easy 1.2V. *Surprisingly enough, many users are able to achieve very good overclocks with this modest amount of CPU voltage. *I would be surprised if sample #1 needed any more than that, sample #2 probably need a bit more, and sample #3 will probably need quite a bit more.
If you are overclocking with power saving features enabled, Gigabyte motherboards will allow you to set the CPU voltage via “Dynamic Vcore” which improves overclocking capabilities while using your power saving features….to unlock this feature; first you have to set the standard Vcore setting to “normal”. *Then set the “Dynamic Vcore” setting to +0.05 and increase as directed below.
Testing for your highest stable CPU frequency
Once the operating system has fully loaded, start up RealTemp. *Now start up CPU-Z and verify that your overclocked settings have been properly applied, and that you are running at your desired CPU, bclock, and memory frequencies. *Each of the sample systems should look like this.
•Sample #1 – CPU = 3000MHz, uncore = 2400MHz, memory = 600MHz
•Sample #2 – CPU = 3150MHz, uncore = 3000MHz, memory = 750MHz
•Sample #3 – CPU = 3450MHz, uncore = 2700MHz, memory = 900MHz
***Note***, if you have SpeedStep (“EIST”) enabled, the CPU speed will fluctuate in CPU-Z and the load changes, please verify values given above WHILE RUNNING YOUR STRESS STEST.
Now start up your selected test program, for example OCCT (CPU) or IntelBurnTest (maximum). *Run the test for just a short amount of time, I usually try to run 3 loops with IntelBurnTest (maximum). *Then reboot the system and return to the BIOS.
1.If the test ran without error, raise the bclock by 10MHz, reboot into your OS and run the test again.
2.If the test failed, raise the CPU Vcore voltage by 0.025V, reboot into your OS and run the test again.
Continue to repeat this testing following the two procedures above, until you meet one of the following three criteria:
•You reach the same bclock speed you identified in step one and successfully pass your stability test.
•You reach your maximum safe Vcore (as identified above), or maximum safe temperature.
•Raising the Vcore is ineffective in stabilizing the system.
Just as you did in step one, if needed you can follow the same procedure for fine tuning here.
Is it stable?
So, once you find your highest CPU frequency by meeting one of the criteria above, and run OCCT (mix) or IntelBurnTest (maximum) for one hour minimum. *I’d like to refer to all this testing as “reasonably stability”. *In my experience, the true test of stability is the regular daily operation of your system, doing what you intended it to do.
The reason we use testing programs like OCCT or IntelBurnTest is to simulate a worst case scenario. *I have never seen any real world application come close to generating the heat that IntelBurnTest (maximum) generates. *But there are a few that can come close to OCCT, like folding or crunching for distributed computing projects, encoding high definition videos, or very heavy multitasking. *But even though OCCT or IntelBurnTest (maximum) stress tests tend to generate more heat, they do not always find 100% of instabilities. In my opinion, the ultimate test is to use the system!
Final Words
Well, that about wraps it up. *Believe me, there is so much more to overclocking. *There are SO MANY settings you can continue to fiddle with, you may have a million questions at this point about all of the settings in the BIOS that we never touched. *They’re valid questions, but not meant for this guide. *My goal was for this guide to get you 95% of the way in 5% off the time. *Hopefully you’re there! *The other settings in your BIOS will be needed to get you to 100%….but if I included those things in this guide, it would be 3 times as long, and much more complicated.
Please feel free to comment, and post any questions. We will do our best to help you out with any problems you may encounter!
This tutorial is made by Jeremiah Allen and found on http://www.techreaction.net