Can't get past 2.5Ghz on C2D

[Nechen]

First off I'd like to say that at this point I keep shooting until I hit something.

I have:

MSI P6N SLi Nforce 650i
Core 2 Duo @ 2.13Ghz E6400
2GB OCZ DDR2-800 PC6400 RAM



Anyway I'm using a Dual Core Center from MSI and the BIOS to adjust my voltage levels. I had my Vcore running at 1.5 - 1.6 and my Memory Voltage at 2.10. I managed to get all the way to 315Mhz x 8 running at around 2.5Ghz. Anything past that and the system locked up.

I know temperature isn't a problem, I have a Zalman pure-copper heatsink and my machine was at around 28c *idle* while running @ 2.5Ghz.

I'm seeing people clock past 3.0Ghz and I really have no idea what I'm doing wrong, only thing I can think of is the RAM timings but I dont have the slightest clue where to begin on that or what any of the dozen values mean, I do have it running @ 800Mhz Dual-Channel.

Any help/advice would be appreciated.
Thanks!

 

[doeden]

I've heard about this too but don't know how to do it.

Anyone wish to comment?

 

[peterhuang913]

is the ram for overclocking or is it value ram?

 

[TheMajor]

Disable stuff you don't need, like themal throttling, etc. Then set the RAM timings to SPD and lower the FSB:RAM ratio to something like 3:2 or 5:4. Increase the Nortbridge/chipset voltage if possible on that board.

This is just to make sure it is not the RAM limiting the CPU/FSB. You can try to get the RAM running at a higher speed afterwards.

 

[Nitestick]

i'm not sure but i'm thinking that perhaps the 650i suffers the same FSB issues as it's big brother the 680i :/

 

[TheMajor]

It can't be worse than the X975 chipset, and I'm at 430 FSB.