Core i7 4.0Ghz Overclock, Help Needed..

[cupofchow]

Ok guys just got an i7 920 DO and im wanting to overclock it, my goal is 4.0Ghz

i7 920 DO
Gigabyte UD5 (F9m)
OCZ Platinum 1600Mhz C7
5870
Corsair H50-1

Bck : 200 = 4.0Ghz

All i have done is set CPU vcore 1.35v Qpi 1.35v, memory on 1.64v (7.7.7.24-1T) in bios. In windows cpu showing 1.328v in CPU-Z and drops to 1.312v load. LLC is enabled.

Now i have ran Prime for 30 mins with out any errors but if take the volts down anymore on the cpu or qpi when i run occt or linX it will freeze some of the way through and the screen goes a sky blue colour and i have to do a reset.


I was under the impression the DO were easy clockers ?

Could anyone help me set it all right.

 

[mmj_uk]

191 x 21 usually works a lot more stabily and on much lower voltages.