Some basic questions, new cooling and oc

[HiCZoK]

Hi guys. I've got myself new cooling to finally replace that stock fan

SilentiumPC Spartan HE923

and only one SilentiumPC Zephyr 92 for case.

My specs are in signature. Bios is updated to latest version.
So... my stock is 1,86 and highest stable (at least in prime95v266 blend test-I dont know any others programs) oc is 2,80 and its the one I am using. Yes I know this is quite much, but Ive read that people are getting 3,15 and so on easily on this model.
Basicly as it is now on 2,8 stable - 1,3125vcore, rest voltages auto. ram 800 fsb 1600
ram clocks 4-4-4-12-1clock per command(1T?)

The highest I am able to boot is 2,97 and no matter if I tune down memory clocks, rise vcore or anything, its not stable. And my temps are fine.

One more thing. Should I put a little fan on mobo chipset? The passive radiator below cpu. It is very hot in touch, but none of my mobo temps are high.. at least hwmonitor says so:

also. Ive positioned the case fan on the back and its taking air out of the case. Cpu cooling is positioned in ram direction and its cooler is blowing air right into the case fan, through cpu radiator.
To add- Psu is right above this. Its one of older cases where psu was in the upper corner of the case with its fan targeting down.

and someone correct me but the basic task is to give every component lowest voltage possible, when it is stable. SO I should start with low voltages and keep first one which will be stable in prime?


I would be thankfull for any tips
Merry Christmass and heppy new year guys!