Prescott Undervolting

rockofclay · Post by **rockofclay** » Fri Feb 13, 2009 1:54 am

Hi there I have a Prescott 2.8GHZ CPU and a GA-85648fx (Sis 648 +Sis 963 chipset) motherboard.

I want to reduce the heat a little, so I was thinking of undervolting. I have tried RMClock, but it seems I can't adjust the Vcore for some reason.

My motherboard bios only supports overvolting.

Is there any Software/Bios mods I could use to do this?

BillyBuerger · Post by **BillyBuerger** » Fri Feb 13, 2009 6:26 am

I wish. We have a handful of P4 and PD prescotts in use around the office here. About half 6xx and 8xx which don't support any power management and about half 9xx which have the ever so tiny underclock from 2.66-3.0GHz down to 2.4GHz although I believe it doesn't change the vcore at all by default. With the 9xx ones, I can use RMClock to undervolt by about 0.1V but that's it. Unless your motherboard's BIOS supports something, you're screwed from what I've been able to find. I believe SPCR reviewed one such motherboard that would actually underclock the FSB when under low load. But that's the only thing I can think of for these old CPUs.

The real fun thing is that these all came with really crappy PSUs as well. So with the power hungry prescott and an extra video card (we do a lot of dual-monitors), these PCs sound like they're ready to take off. I've swapped in some better PSUs, cases and fans where I can. But we still have a couple of really noisy ones.

jaganath · Post by **jaganath** » Fri Feb 13, 2009 12:36 pm

best bet is to get a 2Ghz Northwood off ebay and swap out the Prescott, which are only fit for the dustbin.

rockofclay · Post by **rockofclay** » Fri Feb 13, 2009 2:42 pm

dang its a shame.

The PC's only a spare, so I wont spend any money on it.

No physical voltmods that can be done?