Newbie question: when do I adjust voltage?

[JeffChrisope]

I have dual PIII700s running on an MSI 694D-AR. They handle 933, 966, and 1002Mhz just fine -- Sandra's CPU benchmark or games can't seem to get the temp over 39C. No instabilitities ... but when I jump to 151 (or 2, can't remember) FSB, the system won't even POST. The DLEDs say it's hung at "processor initialization" ...

I've always left the CPUs to autodetect voltage, and use default in the BIOS. Is now the time to up the voltage a little and see what I get, or am I apt to get nothing else? I particularly anxious to push it up a little bit more because the PCI bus speed drops back down to 31Mhz if I can get it up this one more notch, which should make my integrated RAID controller a tad happier.

Thoughts?

 

[Tonec]

Thats a very nice overclock for default voltage. You should experiment with bumping voltage up to .2 over default. Lot of other factors may be holding you back, ram and maybe hitting your cpu limit.

 

[Massa2]

Kick it up a notch or two as it appears you have room if it's working stable now at default...good luck.

 

[shiznut123]

what are your sys. specs.?

 

[JeffChrisope]

Full specs:

MSI 694D-AR (ATA/100 & RAID)
Dual PIII 700/1030 (FSB 147, PCI 37, overvolt +.05V)
1x256MB Mushkin DIMM PC133 rev 2
2x30.7GB Maxtor HD, in RAID 0 array
Hercules Prophet Pro 64MB
some other stuff

Upping the voltage didn't do a thing -- I ran the CPUs (individually at first, since CPU1 has always run about +.05V higher than CPU2, anyway) up to +.2V, and there was no change: at power-up, the machine would go through the first several POST steps, but DLED would indicate a hang at the "processor initialization" step.

The video card never initializes -- I never get signal to the monitor, so I was thinking that the weak link might be the AGP bus ... but the next FSB setting, 152, wraps the PCI bus speed back down to 30, so the AGP theory doesn't quite make sense.

Anybody have any other suggestions, either AGP BIOS settings or ...? I mean, I'm happy with the overclock ... but it'd be cool to go just a liiiiiiitle bit more .... ;-)

p.s. the "overvolt" experiment wasn't at all a waste -- the dual procs were only stable up to 1002Mhz at default voltage; adding +.05V has made 1030Mhz seemingly just as stable, with max heat (after playing Mechwarrior 4 for two hours) only around 40C.

p.p.s. hey ... I wonder if swapping the two CPUs around would yield interesting results?

 

[JeffChrisope]

OR maybe I could set the BIOS setting to "Try AGP first" for video init -- perhaps that could do the trick?

 

[spamboy]

Crank those puppies up to 1.85 V. I do that BEFORE overclocking. Let us know how high you can go with that voltage.

 

[SEOTAIJI]

i am testing my post