q9450 overclock

[Gannef]

I'm currently trying to get my q9450 to a stable 3.2ghz
I've increased the vcore from 1.28 to 1.32..
NB is @ 1.5v instead of 1.3v
everything works fine, it seems stable.. but each time I run prime95 core #4 fails after 3 min, the others work fine for more than 1 hour now.. anyone got any ideas why this is?

sys specs:
mobo: nvidia 790i (asus striker II NSE)
cpu: intel q9450
Ram: OCZ reaper 1333mhz ddr3 @ 7-7-7-16 1.75v
2x 9800 gt @ 610/1920 (standard oc)
2x500 gb seagate barracuda, 7200.11 in raid-0
700w psu OCZ gxs700


Note:
temps are 65-58-58-57 as long as all cores run, when #4 fails they drop to 63-57-57-50

 

[bruce0916]

Your q9450 shluld get 3.2g at stock voltage and work well. Try to lower your core voltage and run again. Have you run prime95 at stock clock? Does it work well?

 

[alyarb]

it's not your vcore, it's your crappy nvidia board, so there will probably be some FSB holes that you will have to work around in addition to bus voltages that need finesse. have you tried above 3.2 GHz?

 

[Gannef]

At the stock speed its fine

it's just that 2 cores seem to perform very bad.. (#1 and 4) so I haven't tried above 3.2 ghz I'll try lowering the vcore this evening, and test again

The mobo is pretty crappy indeed, it has never been very stable with random lockups even at stock speeds.. I had to increase the nb voltage to get rid of the random lockups.. are there any voltages you suggest I should change to get better results?

 

[Gannef]

I've tried lowering the vcore now.. everything below 1.3v would cause an error in prime within 2 min on all cores..
running prime @ 1.3v for 10 min now, no errors yet

btw, nvidia system monitor cpu temps are around 4-5c higher than those of core temp, which one should I trust?