Quick + Safe underclock/undervolt for old AM2 chip

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=assassin=
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Quick + Safe underclock/undervolt for old AM2 chip

Post by =assassin= » Sat Mar 07, 2009 1:13 pm

Hi, I'm just playing around with Crystal CPUID and thought I'd see what happens when I underclock my AM2 A64 3800+ single core down to 1.8Ghz from 2.4Ghz, and it seems not that much difference performance wise in the games I play - it's also a couple of degrees cooler (around 36-37C instead of 38-39C).

I'm mainly interested in what you guys think would be a safe undervolt I could do with zero testing while it's running at 1.8Ghz. I assume as my processor was intended for 2.4Ghz at 1.35v that it could do 1.8Ghz on a much lower voltage without much fuss. As I say, I don't want to have to mess about stress testing in Prime95 or anything, just something that's a little lower and I won't have to worry about crashing - would 1.25v be safe at that speed (and no testing)? Or would 1.3v be a safer bet. I don't want it to be near the limit! Also, is there any way to estimate roughly how many watts I'll be saving?

[EDIT] Also, are these settings saved by BIOS, or will it just revert to normal values on restart? (Crystal isn't enabled at startup).

Thanks for any info :)

porkchop
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Post by porkchop » Sat Mar 07, 2009 4:26 pm

i remember my venice core 3000+ ran at 1.8ghz @1.1v, i could've gone lower i think- but i was limited by the motherboard.. or maybe it was the cpu?

anyways- the voltages should reset every time you turn off your pc, unless you have cool and quiet activated.

Tobias
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Post by Tobias » Sat Mar 07, 2009 4:31 pm

Without changing the fsb, my dual core 4200 does any multiplier on 1.1V

lowpowercomputing
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Post by lowpowercomputing » Sun Mar 08, 2009 4:17 am

My LE-1640 does 2.7GHz at 1.1V.

Suggesting something without zero testing is not that easy but I'd say give 1.1V a try.

=assassin=
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Post by =assassin= » Sun Mar 08, 2009 4:38 am

Thanks for the input guys :)

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