Overclocking A Lynnfield Intel i7 860 on an Asus P7P55D-M

Wednesday, December 30th, 2009

So after all the guff I had to go through getting the Gigabyte board to post with my memory I ended up going to my tried and true brand – Asus. After dealing with the awfulness that is VIA way back in 1998 I have been using Asus boards almost exclusively. Frankly an extra two percent performance or a headache by going elsewhere is not worth it for me. Maybe I have just been lucky or maybe there is a reason Asus is the largest mainboard distributor in the world. Setting all that aside, let’s get to the point of this article. Once I had my shiny new board and processor I wanted to jump straight into overclocking… but oh how things have changed!

As features are brought directly onto the CPU (PCI-Express, memory controller, graphics in some cases) a whole new world of settings must be handled. Of course I don’t give a whit about any of that. I want to find a max cpu speed pronto. Please don’t make me read ten pages of techno jargon just to figure out if I can hit 4ghz. Before we get started make sure you install CPU-Z, Prime95 and ASUS PC Probe so that you can monitor everything. Let’s get to the meat of it.

Finding your max CPU speed w/o HT

  1. Enter BIOS and disable Full Screen Logo from “Boot -> Boot Settings Configuration -> Full Screen Logo” so that you can see what is going on when you boot
  2. Under the AI Tweaker tab set “AI Overclock Tuner” to manual
  3. Extreme Phase Full Power Mode to “Enable”
  4. Your BCLK defaults to 133. Raise this to raise your processor speed. Start out at something moderate like 166 for a 25% overclock. Stability deteriorates around 205 on most boards.
  5. DRAM Frequency – set this to the lowest non auto setting. Now you don’t have to worry about the memory introducing stability issues. For the record you should already be running high end memory for O’Cing. I would recommend DDR3-1600 at a minimum. You want this to prevent your memory from bottle necking your system stability.
  6. QPI frequency you don’t have much control over, but set it to the lower of the two values. You do not want this value over 7500 or so.
  7. VCORE over voltage to .2. This is the max safe voltage for Lynnfield – the default 1.2V + .2V = 1.4V
  8. DRAM voltage to 1.6
  9. Disable HyperThreading from “Advanced -> CPU Configuration -> Intel HT Technology”
  10. These manual adjustments should automatically disable Intel Turboboost, but if you see the options available then turn off SpeedStep and TurboBoost.
  11. Boot into Windows and open up PC Probe and CPU-Z to verify your settings. Run Prime95 and check your voltages and temps for safety.

For the records sake I was able to hit a stable 4ghz using this method. I could probably have gone further, but I was interested in a Hyperthreading O’C because I do a lot of work with digital video. Those extra four threads should make quite the media encoding difference!

Finding your HT CPU speed

  1. Downclock yourself to something reasonable like 165 BCLK again and reenable HT.  The computer does a kind of full shut down and restart when you toggle HT which was at first scary, but no worries.
  2. Go back to AI Tweaker and set your voltage offset to .1 (will have been at .2 from previous test). I found that with my processor HyperThreading did not like the extra voltage used for non-HT oc’ing at all. By doing this I was able to stably overclock to 3.8ghz instead of 3.5ghz.

Finding your max memory speed

  1. Set your BCLK back down to 133 and choose the fastest memory speed you would like to test. You can inch the speed up or down by raising/lowering the BLCK. I was able to find a stable value of DDR3-1700mhz for my DDR3-1600 memory. I kept all other memory settings at their defaults. There is a lot you can do here, but a little bit of memory bandwidth just doesn’t make that much of a difference for the majority of apps.

So now that you have all your information you can combine your max memory O’C with your max CPU O’C and scream along. I hope somebody finds this article useful!

3 Responses to “Overclocking A Lynnfield Intel i7 860 on an Asus P7P55D-M”

  1. Strategia reklamy…

    [...]Overclocking A Lynnfield Intel i7 860 on an Asus P7P55D-M « Tom Sherman's Blog[...]…

  2. I?m now not sure where you are getting your info, but great topic. I must spend some time studying more or figuring out more. Thank you for great information I was searching for this info for my mission.

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