Trouble Hitting FSB 250 on NFII Lanparty Ultra B

[CKTurbo128]

I have a Mobile Athlon XP 2600+ running on a DFI NFII Lanparty Ultra B that is Prime95 stable at 2.5 GHz at 1.85v on FSB 200 and FSB 225. Setting the multiplier at 8x, I tried going for 250. However, as I reach toward an FSB 250, I am running into some stability issues, where close to FSB 250, I even get a corrupt XP prompt (it works fine when I back down to FSB 200 though).

I have been using Geil Ultra Series PC4000 1 GB (2x512MB) memory, which is rated to run at DDR500 speeds. I have tried raising the AGP voltage to 1.6v, chipset voltage to 1.7v, even raising the memory voltage up to 3.0v (even though I have DDR500 rated memory), but none have helped. I am suspecting that using my HDDs on my onboard SATA controller might be an issue (maybe it cannot support high FSB speeds?).

Does anyone have any suggestions on what may be the issue? I would like to get suggestions to those who have overclocked their FSB to 250 successfully on this motherboard.

EDIT: I am using the latest BIOS released by DFI, if that helps.

 

[cirthix]

turn off CPC<-----main restriction
if you are brave, try the 05/05 beta modded bios (works great for me, but reports of instant bios corruption are real) loosen timings. it also helps to put a beefier hatsink on the southbridge and a heatsink on the chip by the agp port, near the back of the motherboard, i forget what its callled

 

[CKTurbo128]

Thanks for your suggestions, I'll try turning off CPC and see if that works. Is there a large performance hit when CPC is off? Also, where can I get a hold of the modded BIOS?

 

[cirthix]

some performance is lost, but it is made up by being able to use higher fsbs (inthe 260 range if yoru ram can do it)

 

[cirthix]

o, and lock agp fequency at 66mhz, that will force the pci bus to 33mhz, and the sata/pata stuff is all on the pci bus, so that will stay locked at normal speeds

 

[cirthix]

any updates?

 

[CKTurbo128]

I guess the official BIOS is holding me back from hitting FSB 250. Do you know where I can get a hold of the modded BIOS for NFII Lanparty Ultra B motherboard? I tried googling for it, but the only results that came back were people mentioning they had it.