How to overclock i7 870

I used Miahallen's approach to explore parameters. But after looking I decided that high bclk's just added to temps on my i7 860. Since you are using a 212+ for cooling, you will be a bit heat limited.

The method:

>Disable EIST, C1E, various C-states. This will mean that when you make demands on your system your cpu won't try to shut down some cores and goose others.

>Jack up your multi as high as possible. On my 860 this meant putting Turbo Boost on Auto, which allowed the cpu clock to rise to 22x across the board. That allowed me to set my bclk to 182MHz for a cpu speed of 4004MHz. For your 870 OTOH a Turbo Boost on Auto should get you 24x.

>Set your desired bclk. 167MHz is a nice starter - 24x167=4008MHz. Remember, Vtt/IMC is needed for high bclk's. The lower the bclk, the less Vtt/IMC you need.

>Set your Vcore and Vtt(IMC) to Auto. Start up monitoring software, then start LinX or something. Watch where the Vcore goes so you will get some idea what the mb thinks is appropriate voltage.

>Set your IMC to 1.19v. Later you can try reducing it.

>Set your Vcore to 1.3v to start. Later you can adjust it up or down as you may need or desire.

>Enable LLC. You're going to be staying far away from 1.4v, so your transient spikes will not go over Intel limits.

>Run your load. LinX is a fine starter, but I find OCCT/Linpack heats up my system better than any other software.

>If you crash, look for BSOD error codes:
0x00000050 << Incorrect memory timing/freq or uncore multi
0x00000124 << incorrect qpi/vtt voltage ( to much/not enough)
0x00000101 << not enough Vcore voltage
0x00000109 << Not enough or too Much memory voltage

My i7 860 ran at 22x182=4004MHz. It needed a Vcore set to 1.3125v, and on load ran a Vcore up to 1.328v.

My i7 875k runs a bclk of 134MHz, with Turbo Boost x4 set to 30x, giving me 4050MHz on load. Vcore is set to Normal + 0.025v, giving me Vcore on load up to 1.344v. Temps are cooler than they were with the 860, though. My Vtt/IMC is 1.1v (that's right: one of the advantages of a low bclk).

Good luck! Have fun!

Edit: Oh yes - If your system runs successfully with a Vcore of 1.3v, lower it, test and keep lowering it until your Vcore is too low. At some point you will find the lowest Vcore that will support your OC. That's the spot you want.
Edited by ehume - 10/9/10 at 10:12pm