Friday, 15 July 2011

Manually Overclocking the new Sandybridge

Over the past week I have been forced to buy a new gaming rig as my dog managed to urinate though the side panel of my case, straight onto the motherboard, memory, graphics card and power supply unit, leaving me completely without both a gaming machine and any web browsing capabilities; which in my book is like having one of your appendages removed.
So I found myself facing a decision...
i) Replace the bits that had been ruined for similar / identical parts, or
ii) To upgrade from the 1366 socket type completely. Well seeing as I am writing this blog, I am sure that you have already guessed what I decided to do!
Well after some deliberation I decided that it would be best to upgrade to the latest chipset from Intel rather than pump my money into a [soon to be] obsolete socket type. I aquired:
 ASUS P8P67 Deluxe,
8GB DDR3 1866 9-10-9-27 Corsair Vengance (blue),
and the intel i7 2600K processor.

Agreed, the performance increase is not as noticeable as if I were to upgrade from the LGA775 socket type for example but none the less there are still great gains to be had when you wake the chip up out of its factory settings and start pushing the boundaries with overclocking!
I have always enjoyed overclocking, my memory, GPU, Processor and totally love seeing how far I can push my system and what gains are attainable. On a side note, my previous graphics card (MSI GTX 460 HAWK) Was the best card I have ever owned - the overclocking potential was phenomenal.

Disclaimer: Overclocking has its risks, and if you are not confident in tinkering with any settings that I am going to explain, then I urge you not to do so as you could end up ruining your components. The second that you overclock your processor, your warranty will be null and void! I will not held responsible for any damages or losses incurred!

This guide is aimed at the beginner, as I will try to explain as best as I can 

Okay first off you will need a few applications, both to monitor your components and to test their stability with their new settings.

CoreTemp - this application will tell you the temperature on each core of your processor.

CPUZ - This tool shows you every detail about your processor and the clock speeds that are set.

Prime95 - This is a stress test program that utilises 100% of your processor usage to establish how stable your overclock is.

OCCT - Again this is another stress test program like prime95 but I have found that on occasions, this program will find a weakness in the overclock where prime95 runs smoothly all night!
I will try to keep this as simple as possible so that everyone can follow it easily.

(VCC)when overclocking your processor, to enable it to perform faster you may be required to increase the voltage to the processor  - This also depends on how much you overclock by. You may find that you can increase the speed of the processor by a moderate amount without having to touch the voltage. I will go more into the maximum safe voltages in a moment.

What voltages can you expect to set the VCC to when overclocking?
Here is a guide, and I say guide as every CPU is different; some may require more and others may run perfectly on a lower voltage!
4.0-4.3GHz 1.300v-1.325v
4.3-4.5GHz 1.325v-1.375v
4.5-4.8GHz 1.375v-1.450v

(BCLK)This is the frequency that the processor runs at, unlike overclocking with other processors where you would be expected to change the frequency and multiplier; With the Sandybridge I urge you not to change this from the default 100.0 unless you know what you are doing, as it affects a number of different settings which can bring about not only instability but possible damage to other hardware. Being at a set 100 makes overclocking pretty simple, if the multiplier is at 45 for example and the BCLK is at 100 then that would equal a  total clock speed of (100x45) 4500Mhz or 4.5Ghz. This clock speed is easily attainable with air cooling and as I'm sure you will agree is a great deal more performance than the stock speed of 3.4Ghz.

This is multiplied by the BCLK to give you your total clock speed. This is the main setting that we will be tinkering about with to get the most out of the processor.

A very important factor where overclocking is concerned is the temperature! The more voltage that you put into your chip, the hotter it is going to get under load. You need to keep an eye on the temperatures to enable a safe overclock!
Ideally you do not want your temperatures raising above 72C as this will likely reduce the longevity of your processor and could possibly cause damage.

Air Flow:
It is important that you have adequate air flow in your case to expel the hotter than usual air produced during the stress testing phase. for more information on case air flow, please do some googling on cable management and case fan configuration.

CPU Cooling:
I recommend that you upgrade your CPU cooler to a more efficient type than the stock cooler provided by intel. Don't get me wrong, the cooler that the retail version comes with is adequate for stock speeds, however when overclocking you will find that this becomes your limiting factor as far as temperatures are concerned. A great cooler that I can personally recommend is the Megahalems Rev B using a push/pull configuration with 2 x 120mm fans. However for the more extravagant of you, water cooling is always an option.

Thermal Paste:
Please follow this link if you need any information about thermal paste :
Okay, this guide is really geared around my motherboard (the P8P67) However many of the settings may be similar to those that I am outlining in this guide. If you are at all unsure then please check your motherboard manual for more information on the settings.

How much will you be able to overclock by?
1. Approximately 50% of CPUs can go up to 4.4~4.5 GHz
2. Approximately 40% of CPUs can go up to 4.6~4.7 GHz
3. Approximately 10% of CPUs can go up to 4.8~5 GHz (50+ multipliers are about 2% of this group)
The above was a statement by ASUS regarding overclocking on the P67 chipset.
Every processor is different. You could have 2 identical processors with the same batch numbers and one may be able to clock easily to 4.8-5.0 and the other may struggle to get past 4.5, it is simply the luck of the draw!
I do not advise in attempting a 4.7Ghz+ overclock on air cooling as I do not believe that the temperatures will be viable, but it is entirely up to you what you do with your system and you may find that your processor runs cooler!
Right then, let's get to it!
Firstly uninstall the EPU software (if you installed it in the first place). This software over and underclocks your system and lowers / raises voltages for a small overclock or underclock to save power.

BIOS Settings:
C1E and EIST = enabled

 The 3 settings below can be changed to increase the overclocking range above what we are trying to achieve, so just leave them as Auto for this tutorial.

Duty Control = Auto
Phase Control = Auto
VRM Frequency = Auto


Speedstep = Disabled.
LLC or Load Line Calibration = Auto.

Asus reccomend setting LLC to HIGH, however this may increase your temperatures and push a little too much voltage through your processor than you want, normally leaving this on Auto will be fine unless you experience terrible stability with the outlined voltages.
Downclock your memory frequency to 1333Mhz if you have faster modules installed - This will ensure that you are testing the stability of your processor and not your memory.
I am not going to go into detail for these settings, as this is not meant to be an advanced guide. If you wish to know more about these settings, then google it!

If you wish just to get a gain out of your processor without pushing it to its limits, then choose a clock speed that you are happy with and set the multiplier accordingly. Next set the VCC to the lower end of the voltage guideline, save and reboot your computer.
4.0-4.3GHz 1.300v-1.325v
4.3-4.5GHz 1.325v-1.375v
4.5-4.8GHz 1.375v-1.450v
If your computer fails to boot into windows (BSOD), then go to the next paragraph below otherwise go to the "System stability" heading.

If your processor does not have the required voltage it needs to boot, then the chances are that you will receive a BSOD with the error code (x000000124).
If this is the case, then do not worry it is simply a case of upping the voltage. Upping the voltage by 0.025V should remedy this (you may wish to raise it by a smaller amount).
If your computer fails to boot after a BSOD then you may need to clear the cmos (on the P6970 there is a pin hole on the rear panel with "cmos" written above it). Just press this in and hold for 1-2 seconds then reboot. Please note that when you clear the cmos, your motherboard will lose its saved settings and you will need to manually reconfigure them again. Just remember what voltage you set it at previously and increase as necessary.

System Stability
Okay, so you booted up into windows without a problem... good!
Load up CoreTemp or HWMonitor and make sure that your ambient temperatures are acceptable. If with a mediocre overclock you are experiencing high temperatures at idle, then this could be an issue with your CPU cooler not being seated properly or the thermal paste not being applied correctly. It may also be an issue with your air flow in your case. If at this point you are seeing temperatures above 50C then I suggest that you forget about overclocking until you remedy this problem.
If all is good with your temperatures, you need to run CPUZ to check that the settings you put into the BIOS are correct and that the CPU is overclocked as desired.
Okay now for the stress testing.
Leave CoreTemp or HWMonitor running so that you can monitor the temperature whilst running the stress test. I recommend HWMonitor just to keep an eye on the VCC to ensure it does not stray above safe limits.
Load up Prime95 and select the top choice (Small FFTs). Number of threads to run should match the number of threads on your processor - for i7 2600k (with hyper threading enabled) should be set to 8.
Press OK and the workers will start, you will notice in any CPU monitoring gadget or task manager under performance that every thread on your processor will be running at 100%.
Keep a diligent eye on your temperatures at this stage for the next 20 minutes or so and this will give you a good indication of your max temps. As Prime95 continues to run different algorithms, you will find that your temperature will deviate. You ideally do not want to see your temperatures going over 70C at this stage, as it may push up to 75-80 later on in the test which is outside of your desired temperature range.
If your Prime95 runs without a hitch for a few hours without your temperatures going over your threshold then I would say it was safe to leave it running over night. This will prove a stable overclock!
If your system fails during the stress test with a BSOD then refer to the "BSOD" heading above.
If your computer fails with an instant shut down then this points to different issues that will need investigating further (usually PSU from my experience) however it could be a magnitude of other issues (like dogs urinating in your case) lol. 

Experiment with your settings, try to lower your voltage on the VCC to the point where stability becomes a slight issue, then crank it back up just a little to ensure that you are not pushing too much voltage through the CPU than is required. Likewise if you are still having issues with stability regardless, then try altering the other bios settings (although refer to another more detailed guide for this to ensure you understand exactly what the settings should be).

After this reasonably short and relativley easy to follow write up, I hope that you are now more clued up with the basics of overclocking with Sandybridge on this particular motherboard, however the settings between different motherboard models are pretty much the same.


  1. I've never been so confident with myself to try overclocking...

  2. this is a really helpful guide! cheers i followed your blog looking forward to more like this

  3. very going to bookmark this, follow you, and when i have the time im gonna try to overclock my macbook pro. because i havent overclocked anything before. thanks a ton man.

  4. whoa really nice guide man, thanks a lot! :3

  5. I want to try out the new A8 CPU with graphics build in. Has anyone tried it yet ?

  6. I've never overclocked anything. My old PC is probably not even worth overclocking anyway. When I get new PC, this will be probably useful.

  7. I was going to overclock my cpu, but its multiplier is locked at 13 and its just too much hassle for not as much improvement =/

  8. WOW, very detailed man! I'm no expert on overclocking but I have dabbled.

  9. This is a nice guide! I've been searching for info like this since my old Fujitsu cant handle running photoshop and my tablet driver at once, so I was gonna buy some new parts and upgrade my rig ( to handle Starcraft 2 too of course ) With this method do you think that would work?

  10. +follow btw, love tech blogs

  11. not sure exactly what processor your fujitsu is running, however i'm sure you could tinker around witht he BCLK, VCC and (possibly) the multiplier if it is unlocked. Also be careful raising the voltages - do not go by the references in this write up as laptop CPUs are low power consuming, to enable higher efficiency with battery power.
    Be sure to keey your eyes on the temperatures aswell (google what the max limits are for your specific chip are).
    So yes and no, yes I expect you would be able to overclock and NO, do not go by this guide, it is geared around the i7 2600k - a processor which can take relativley high voltage in comparison to previous versions