How much over 12V do I need to be?

[tRidiot]

I've been trying to troubleshoot my OCing problem for over a month now. I have tried 2 different Opty 165s, 2 different DFI motherboards, RAm underclocked, etc. No matter what I do, even underclocking my CPU (lower multi), I can't get above 275 HTT stable.

I just checked my voltage on my Silverstone PSU after reading that someone else with the SAME PSU is having random reboots, just like me. Not really BSODs or lockups, just sudden reboots. Here are my results:

2430 MHz:
Idle - 12.10v
Load - 12.02v

2520 MHz:
Idle - 12.10v
Load - 12.02v (StressCPU fails both cores in a few mins)


Is it possible I'm getting some rare fluxuations in voltage that are causing my reboots? It will obviously be hard to catch this, as if I'm typing or whatever and the computer shuts down, I'll look down to see the DMM, but I may not catch the low reading (if there is one). And of course, if I'm AFK (or drunk ;) ), then of course I won't see it.

Any suggestions? I'm just about fed up with having 2 good boards from a reputable manufacturer, known for overclockability, 2 CPUs ALSO reknowned for their headroom, high-end DDR500 RAM that is run at stock timings and at underclocked timings, MemTest86+ stable... and STILL held back to an OC significantly below the norm reported here for Opty 165s. :( Heat also doesn't seem to be an issue, either. I'm keeping an eye on it with MBM and it's pretty cool most of the time - mid 20s idle, high 30s load.

Suggestions?

[tRidiot]

Just bumped core voltage to 104% (went from 1.33 to 1.38) and StressCPU seems to be more stable (been running a few minutes now), but I lost .01v on my system voltage. Now instead of 12.02 at load, I am at 12.01 at load. Is this a symptom that I may be close to the max my PSU can put out? Should I try bumping things a bit more?

[LordDarik]

Your voltage is fine, if you really feel it is a problem than you can always adjust the PSU's pots. What are you measuring the voltages with by the way?

[tRidiot]

A digital multimeter on the +12 and - of a molex connector.

Is this not the proper way to do it?

[Know Nuttin]

A .01v differential is nothing, You have to remember that it is very very difficult to maintain 0.000000000% fluctuation in voltage, whether you are comparing idle to load or even just sitting at idle.

[tRidiot]

I'm gonna push it some more over the weekend, take more readings, up my voltages to CPU, LDT, Chipset, RAM... see what I can get out of this thing. :)

I'm not sure if the Silverstone has internal pots to adjust, does it? Pullin' all this stuff out again is gonna be a major pain.... <sigh>

[Know Nuttin]

Yes, the Silverstone has an internal pot for +12v, which affects the +5v as well. Keep this in mind when adjusting

http://lp.pcmoddingmy.com/albums/userpics/Silverstone/ST56ZF/16.jpg

It's the VR201+ that's labelled in the picture.

[Oklahoma Wolf]

Some of the early Zeus 560W units came from the factory with the 12v/5v adjusted too low - this may indeed be one of them. Silverstone has been pretty good so far about not voiding the warranty when adjustment is needed.

[tRidiot]

So then, would you recommend that I adjust this upwards a bit? If so, how much? Would this help me at all or is it just fixing something that doesn't need it to begin with?

[Oklahoma Wolf]

I'd leave it be if it's still over 12v and the system is doing ok. If not, bumping it up to 12.3 or so should be safe.

[tRidiot]

Ok good to know. So if I run into problems as I OC higher, I'll bump it up a bit.

Thanks!