4 sticks versus 2 sticks RAM overclock failing, asus P5B Deluxe

Greetings,

Decided to give my E6300 based system a revision with Windows 7 and a new OS drive along with another 2 gigs of ram (for a total of 4). Made the updates, and the FSB400 overclock I had been running for three years failed.

New memory (mushkin) matched the old (corsair) in speed (5-5-5-12).

Started to read that 4 sticks of RAM is a bit tougher for the northbridge to handle versus 2 sticks on P965 chipset systems. That true?

I've tried throwing a bit more voltage at the northbridge and RAM, but still can't hit FSB400.

FSB333 seems stable, but I haven't stressed it yet.

Anybody with an older system/memory of dealing with the Asus P5B have any tips as to where I can start to see if I can get to FSB400 with 4 sticks of RAM? Thanks!

Have done some more reading, and the general feeling I get is that it is tougher to have all mem slots filled with a P965 DDR2 system and get as good OC as with just 2.

Perhaps I'll poke around on the motherboard overclocking section and see if I can look into the Asus P5B specifics, since I think the motherboard is the issue here.

At FSB430 right now, and will stay here. Prime95 stable for 8 hours after leaving this morning, cpu peaked at 54C, system 34C.

Actually was able to bring down the voltage on the ram (1.9) and everything else other than CPU is lowest voltage at this speed. Issue seemed to be greater vdrop for CPU with the additional ram. Kicked it back to stock levels and the board took off again.

Running 5-5-5-12, only thing I couldn't get was lowering the TRFC from 42 down to 35.

Going to research what TRFC means in terms of speed, I know some 2x2 kits need to go even higher to 54 to be stable, and see if I can tighten up the speed a bit.

Happy that I am able to give a 4 year-old system a couple of more years of service.