underclocking a AMD Athlon 64 3000+

npoe1

Senior member
Jul 28, 2005
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What is the problem when you under clock a processor?, I under clocked my AMD Athlon 64 3000+ below 1 GHz, and my computer didn?t boot, so I want to know why, and what was the problem?, I used a HT link of 166 MHz and a multiplier of 5 so I thought that I could get a 830 MHz processor but the computer did not boot, I know that most people over clock, but I want to under clock it even more, does any body know the limitation and how to overcome it?
 

dug777

Lifer
Oct 13, 2004
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Originally posted by: smopoim86
why the frigging crap are you underclocking

so it runs much cooler? You'd be able to have a VERY slow & silent fan on it...
 

unmerited

Member
Dec 24, 2005
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You could try undervolting the processor allowing you to use a slower, quieter fan. I have my xp2400+ undervolted by .1 (all that my mb will alllow) which lets me run a quiet 80 mm Nexus and still keep it cool. YMMV but you can experiment.
 

StrangerGuy

Diamond Member
May 9, 2004
8,443
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Originally posted by: dug777
Originally posted by: smopoim86
why the frigging crap are you underclocking

so it runs much cooler? You'd be able to have a VERY slow & silent fan on it...

Underclocked and undervolted A64s doesn't even need a CPU fan to run.
 

Gronich

Member
Jun 18, 2000
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I'm currently underclocking my A64 3000+ (Winchester) to 800Mhz (4multix200HTT) @ 1.025v and my XPM to 533 (4multix133FSB) @ 1.000v.

I don't know why you couldn't boot at 5multix166HTT unless you used to little voltage or you have a memory issue.

I suggest downloading RMClock (& CPU-z to check the CPU speed etc) - It allows you to adjust the multi/voltage within and will show you the allowable voltages the CPU supports.

I used to run my 3000+ at 9multix280 (2520Mhz) @1.55v and 4multix280 (1120Mhz) @0.900v so going below 1Ghz should allow a core voltage of less than .9 volts.

I don't think a 3x multiplier is available so I don't recommend trying it.

So I would start with a 4x multiplier and 200HTT @ 1.00v and start from there.
 

Zap

Elite Member
Oct 13, 1999
22,377
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Try leaving the HT link alone and just lowering the multiplier one notch at a time, plus lowering voltage. You may not be able to go below 1GHz, but it should run cool and still perform decent. I have my Sempron 2600+ running at default 1.6GHz (no Cool and Quiet) and undervolted to 1.2v.
 

furballi

Banned
Apr 6, 2005
2,482
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My Sempron 3100 Paris is running at 1.3GHz with Cool n Quiet ON. The fan is OFF about 95% of the time because SMART doesn't turn ON the fan until CPU temp hits 40C. Get a better case or better CPU cooler and use Cool n Quiet.

Lowering the core speed is not an effective method of cooling the CPU if the case has lousy air flow. Going from 1200MHz to 900MHz will only reduce the idle core temperature by 2 or 3C. This is NOISE when one accounts for the variation of the incoming ambient air temperature.
 

imported_ST

Senior member
Oct 10, 2004
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To OP: Curious why you aren't running AMD CnQ utility? You'll get the best of both worlds: low clocks and voltage at lower usage and plenty of hp when you do need it. Combine this with undervolted fans via SPeedfan or so and you can have a very quiet and cool system.

As an example here's my setup when I'm idle or lower cpu utilization:

http://www.geocities.com/stranx44/temp/sp29a.jpg

And here it is when going full blown 100% CPU usage:

http://www.geocities.com/stranx44/temp/sp29b.jpg
 

Zap

Elite Member
Oct 13, 1999
22,377
2
81
Hmmm, was just doing some testing on my Opteron 144 and it won't POST at 4x200 (though I thing 4x multiplier is invalid). It POSTs fine at 5x200. It won't POST at 1.00v but will at 1.10v all the way to default 1.8GHz. My Sempron also exhibited similar behavior with voltage.