Low 12v crashing machine, d@mn Prescotts!

[Mingon]

Have got my Prescott running at a nice 3.7ghz in an asus p4r800 (ati rs300) with watercooling but the damn thing kept crashing. It wasnt heat as it doesnt exceed 40c and whilst I am not adding much vcore I suspected it was something else. Using the asus Probe I am getting readings of 11.1 under load (F@home) and 11.7 when idling!. Whilst my PSU isnt the greatest at the moment (thermaltake 420watt) I didnt expect any issue considering it was powering 2 x mobile xp's @2.266 (my a7m-266 died :-( ) Oh well anyone got any decent PSU suggestions?

Edit - Could it be the motherboard? I am tempted to get an ic7-max to push on for 4.0ghz

 

[o1die]

I use the ratio settings to overclock my 2.8c. In sync, at 1:1, I was able to run at 3.36 (240 for both the cpu and memory). By using the 333 setting for memory on my msi board, I increased the fsb to 260 (memory runs at about 413), and the cpu runs pretty stable at 3.64. At 270, my win2k crashed hard (nothing but bluescreen errors), and I had to format and reload windows. You'll just have to try several voltage and memory settings until your rig is stable. I run my cpu at 1.55, and the memory at 2.60 volts. Anything higher and the heat causes instability. At those settings, my cpu runs at 48-66 celcius. I use a sparkle 300w with single 12cm side fan, and highly recommend it. It helps cool my cpu, and is virtually silent. It has 18 amps on the 12v rail.

 

[spliffstar69]

sometimes pat or the other feature enhanced mode or turbo mode may make it crash more often.

 

[Stormgiant]

Mingon, what's the vcore on idle/full ?

Asus are know to have pikes between.. sometimes, when pushing the cpu, the vcore drops to a level that makes the machine to crahs or reboots.

 

[AdamK47]

Ah ha! I just posted something similar to this:

http://forums.anandtech.com/messageview.cfm?catid=28&threadid=1382816&enterthread=y

I ended up getting a new 550W Antec PS

 

[trexpesto]

Edit: double post

 

[trexpesto]

Could it be all the lights and fans?? Try unplugging some of them and see what happens.

My enermax non-noisetaker has 33Amps on the 12V rail. That should do ya.
The noisetaker split rail ones have a separation of rails might help. Then you can keep all your fans and lights on one and the CPU on another.

The Antecs have the True Blue one with a blue led fan if you are looking for more trouble