Help with Over clocking on a DFI DK x48 2trs

[Swordfish125]

Just built my new system specs:

Q6600 2.4ghz
4gb OZC Platinum 1066 RAM
DFI DK X48 2TRS Mobo
500gb HDD
Sapphire 4850 512mb
Samsung DVDRW
Noctua CPU cooler

Right, I can run the system stable at stock speeds 2.4g with the ram sett at 1066 (divier is 266/1066 in bios).

I have over clocked the CPU to 3.0 (333x9) and 3.2 (400x8) and the cpu is totally stable under OCCT, prime 64bit. When overclocking the CPU i set my Ram to 800 (333/800 or 400/800 divider in my bios). This is stable at 1.34v.

However when I set my Ram to 1066 (333/1066 or 400/1066 divider) prime 64bit fails immediatly. I can run OCCT stable, Orthos stable and Prime 32bit stable. It is only prime 64 that fails, normally after about 2 seconds.

I have tried upping voltages, max were: CPU 1.45v, VTT 1.35v, NB 1.4v, SB 1.5v. Nothing seems to make a difference.
I was thinking of taking VTT upto about 1.4-1.5 but dont want to break stuff.
RAM is 2.2v, timings of 5-5-5-18, set to OCZ specs. All my toher RAM settings are at auto.

So im really confused. My ram can run at 1066 when at 2.4ghz but not when the CPU is higher. So something is going wrong somewere. What baffles me more is that OCCT and Prime 32bit is stable but 64bit prime isnt.

Ive actually run the system at 3.2ghz ram at 1066 and played crisis ok, it just bugs me that prime isnt stable.

I will admit that the DFI settings are a bit beyond me!

Hope you can help, ive tried several forums to no avail so far.

Thanks!

 

[Swordfish125]

im guessing ppl are as stumped as me?

 

[mhouck]

I have the same board and basically processor, but I don't the higher timed mem. You probably want to check with the DFI forums. At least there you are sure there are people who have worked with your board and bios.

One thought, flash the bios update on their site if you haven't already.

From your post, I assume you have done these things already but worth the suggestion.