Has anyone ever underclocked a CPU? Sounds a bit counter productive, but I have a AM2 X2 4200+ CPU, that I’m going to use to run XBMC and 2 cores at 2.4Ghz is overkill. Not only that but I’d like to keep power use and thus heat, as low as I possibly can. I’m assuming I can just pop into the BIOS, lower the FSB (or AMD equiv) to whatever my target speed is (probably 1.8Ghz) and then keep lowering the voltage til its not prime stable. Anyone see any problem with that? Thanks!
That should be fine. I used to do the same thing on the old E2160 I had. It used to run as my file server at 1.6Ghz and 0.9v. You may be able to drop the multiplier rather than the FSB although I can't recall if this was possible on the old K8 processors.
I found that I couldn't reduce HTT below 200 and my board didn't have multiplier support.... hopefully some DO.... and you have options. The thing to remember about underclocking is that you can't keep dropping the MHz and volts forever. The CPU needs a certain amount of voltage to work at all. Picking some random numbers.... you might hit 2GHz at 1.15v, but 1.6GHz will still need.... 1.15v
yea its stable and works what i advise however is to create profiles in AMD overdrive... so when you do want an extra umph you can just activate a second profile...
I've done it quite a lot with Socket 775. I found that all (except a knackered QX9650) would run stock settings at 1.1V and at 1.6GHz would barely increase temps under load.
Yeah I've had a play when I used my i5 670 as my file server, ran it around 1Ghz at 0.9vish Just have a play, there's no sure way to do it
I would say be careful - it doesn't always work. I originally set my CPU voltage on my AM3 963BE to 1.25 when I first built my system. I suffered no end of cold-boot issues. It would take 4 to 5 times before the system would boot up. This lasted for a week until I identified the problem. When I set the voltage to 1.375 (the recommended setting) it worked first time every time. So be careful when under-volting as you may not have enough juice for your system.
Sounds like you reduced the voltage but not the clockspeed! Not surprised you suffered cold boot issues, more so that it was a week before you changed it back!
