LP DK P35 T2RS Refuses to do over 400FSB

[ExcaliburMM]

Hey Anandtech,
I recently got an E6400 off a friend, and swapped out my E2140.

With ease and still familiar from OCing the E2140, I got the E6400 up to 3.2GHz, or 400*8.

However when trying anything above 400, (405, 410, 415, 420, 425), I get no display from my video card and have to do a jumper-based clear CMOS, which is a bit of the pain in the ass. After seeing that 405-425 are all the same nonworking, I'm thinking that its definitely the board holding me back. Is 400FSB max for a P35, especially one as nice as this?

Details
E6400 400*8 @ 1.296v
2x1GB DDR2 800 1.8v @ 800 1.95v
North Bridge @ 1.37v over 1.30 (IIRC) stock.

Bumping NB didn't do much nor did taking the RAM timings down. Am I missing something or is this the best the board is going to do?

 

[yh125d]

Lock the pci-e bus frequency to 100mHz, and lower your ram back down to 1.8v

 

[ExcaliburMM]

Lock the pci-e bus frequency to 100mHz, and lower your ram back down to 1.8v

PCI-E is already locked, and I think the RAM enjoys the extra juice because when I OC any further, the divider has it going to like 811MHz. There's no lower divider. :C

Current divider is 333/667.

 

[EarthwormJim]

You may need some active cooling on the northrbidge, it could be overheating.

Also what is your FSB termination voltage at? It may need a bump.

 

[EarthwormJim]

You may need some active cooling on the northrbidge, it could be overheating.

Also what is your FSB termination voltage at? It may need a bump.

I used to have the same board, it would do 470mhz FSB on a Core 2 Quad (xeon x3210 8x multiplier).

Wierd, edit button posted another message...

 

[ExcaliburMM]

Thanks Jim, I'll check that out and report back.

 

[Hyperlite]

Thanks Jim, I'll check that out and report back.

If anything i would say northbridge voltage...i doubt it's heat, you'd probably have some instability in normal operating before it would outright refuse to boot. It would seem the same for voltage...but i've seen stranger things happen.

 

[ExcaliburMM]

What would be the max safe 24/7 operation voltage for the Northbridge? I know with vcore its generally good to stay below 1.4-1.5v for 24/7 use, but am not sure what it is for NB.

 

[yh125d]

I wouldnt go past 1.5v without active cooling

 

[EarthwormJim]

What would be the max safe 24/7 operation voltage for the Northbridge? I know with vcore its generally good to stay below 1.4-1.5v for 24/7 use, but am not sure what it is for NB.

I went with 1.45v for my quad at 470mhz fsb. Watch your temperatures though, when my northbidge went above 65C Windows would blue screen.

What stepping is this e6400? You may be at it's maximum speed.

If you read some older e6400 reviews, 3.2-3.4ghz was not unheard of being their max overclock.

If you really want to eliminate the motherboard being a potential for holding you back, drop the multiplier on the CPU and see how high you can go. A lower multiplier is less stressful than a higher one, but it can still give you an idea of your motherboard's limit.

 

[ExcaliburMM]

I went with 1.45v for my quad at 470mhz fsb. Watch your temperatures though, when my northbidge went above 65C Windows would blue screen.

What revision is this e6400? You may be at it's maximum speed.

I may have to ziptie a 40mm fan to the NB. :X

Also ignore the paint stuff, I was posting it on a forum full of less tech minded people, and such circles were required to illustrate the point.