Can't seem to get my MOBO at 400 fsb

[battousai831]

Hi all, I've got a Asus P5q pro MOBO that i can't seem to get to be stable at 400 FSB. It seems like i've tried everything but nothing seems to work.
System Specs:
Core 2 Quad 9550 2.83 (8.5 Mult)
8gb of drr2 800 ram (four two gigabyte sticks)
500GB HDD
ATI 4870
Does anyone have any suggestions?
I've had my NB volts up to 1.42, Dram should be at 800 with a 1:1.
Cpu has gone to 1.3, also tried lowering the multiplier.
Other random settings: PLL, Had it at 1.6
FSB Term: 1.26
Asus Performance level: 11
CPU GTL: .65
CPU Clock Skew: 400
NB Clock Skew: 200
Dram timings: 5-5-5-18
2t command rate.

What happens is every time it seems Prime 95 fails the First two cores. System seems completely stable at 375 * 8.5 with lower volts. Haven't primed it for 24h but thats because I'd like to make it to 400 FSB.
Also case is an Antec 300 with 5 120mm fans.
CPU cooler is http://www.newegg.com/Product/Product.aspx?Item=N82E16835186134 (AC Freezer 7)

Thanks in advance for any and all help.

 

[bosshoss]

I have the EXACT same problem with my P5b-E. No matter what I have tried, (upping ram, and CPU voltages, loosening ram timings, etc...) I can't seem to get mine stable at 400. I either have to run it with the FSB at 396, or 404. For some reason anything falling within that range just will not yield a stable overclock. I have heard of a few others with the same problem on some of these ASUS boards. I would like to find a solution to this as well...

 

[battousai831]

Bump, hopefully somebody knows something.

 

[roadrunner197069]

Try with less ram or give the ram more volts.

CPU needs more volts.

Some of your other settings are whacked try setting most things to auto.

 

[gamerk316]

My XFX 790i can reach 400 FSB...guess its really Intel mobo's that stink at ocing...

As above, try less RAM and/or more Watts.

 

[battousai831]

Alright i just tried a few more things, Tried everything auto cept cpu volts which i took up to 1.375 and dram which i put at 2.1. also tried setting nb to 1.5v. still fails p95 instantly. Sometimes it just crashes on prime 95.

 

[battousai831]

http://forums.techpowerup.com/showthread.php?t=65409

Thats the custom bios.

 

[chemicallymark]

Alright i just tried a few more things, Tried everything auto cept cpu volts which i took up to 1.375 and dram which i put at 2.1. also tried setting nb to 1.5v. still fails p95 instantly. Sometimes it just crashes on prime 95.

I had a 790i Striker Extreme 2 and found it had loads of FSB "black holes".

My RAM was rated for FSB 400 as was the board.
But I could not set it above the stock setting of the CPU (E8400) of 333...

After fiddling a bit I tried in between FSB settings. e.g 407, 411 433, etc. etc.
I'm not sure exactly about your board stable regions but the higher the FSB the higher your NB and CPU voltage need to be.