I will go with "just depends" . My E8400 with a mild overclock 3.0 to 3.6ghz runs fine with it on. It reduces the multiplier to 6x from the stock 9x reducing clock speed to 2.4ghz from 3.6ghz with a 400mzh FSB. You just need to play with your system and see if it is stable. I do have to turn it off for anything around 4ghz to be stable.
Good point. The oc seems stable after a 1 hour burn-in at 100% cpu utilization on both cores but that was with speedstep disabled. I read a review at legion hardware that said the max oc on this cpu was 3.3ghz but I know it has to go higher than that if its not even breaking a sweat from 2.4 to 3.0ghz. Ive read that the board is stable up to 310mhz and the current oc is 12 x 250. Id love to get an aftermarket cooler and try pushing it to 3.4 or even 3.6ghz. After Im satisfied with the results, I will enable speedstep and see what happens.
I just OC'd my i7-920 and got it stable with:
base clock: 167 MHz
cpu vcore: 1.2v
LLC: On (level 2)
C1E (enhanced halt): off
C2/C6/C7 state support: off
cpu mult: 20
uncore mult: 16
QPI mult: 18
mem mult: 8
I use the Corsair H50 and after a 24 hour prime95 blend torture test the max T junction temp ended at 63* C on one core but the others all had a 59* C max.
Anyway, I have two questions.
1) When I enable Turbo Boost, my cpu multiplier seems locked at 21. Even when running another prime95 blend for 2 hours it stayed at 21. Is that the intended purpose of Turbo Boost; to just add 1 to your multiplier constantly?
2) When I enable EIST (Intel's speed step), my multiplier never reduces and my core voltage stays at 1.18v and rises to 1.2v under load. This is exactly what my core voltage was doing before I enabled EIST (Actually, I was seeing a voltage droop under load before I enabled LLC, but with it on I saw a small voltage increase under load, up to what I set the vcore to in the BIOS). Is this out of the ordinary?