Would underclocking an XP cause it to use less electricity?

RU482

Lifer
Apr 9, 2000
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I am trying to configure a small Aopen H340D uATX desktop case with an NV7M and an Athlon XP. The power supply is 180W (I don't know any more than that about it yet, will know exact spec when I get it monday). I have an AthlonXP 1800+, and I was thinking of running it at 100FSB instead of 133. Would doing this make the CPU run cooler and/or use less power?, thus decreasing the demand on this relatively small PSU.

OR, would I really gain anything over the 1800+ by buying a duron 1Ghz or 1.1Ghz, as far as power consumption?

Oh yes, I am also using a low profile JAC301C-A copper HSF.
 

Migroo

Diamond Member
Jul 14, 2001
4,488
9
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I'm not sure, however:

If upping the voltage causes the CPU to create more heat, then I would assume the reverse is true.

I would also assume that a percentage of power consumed comes out as heat, and if this percentage stays constant, then if less heat is produced by undervolting, so therefore less power would be used.

I may be completely wrong though... just test it out for some proper evidence.
 

motojeff

Member
Mar 21, 2002
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yes and no.

when the cpu is idle, running it at a slower frequency will save power.

when the cpu is doing a task, a certain number of clock cycles are required to accomplish that
task. therefore, the same amount of power will be consumed, but it will be consumed over a greater
period of time.

this effectively lowers your average power, but your peak power is the same.

i think the need for a larger power supply is largely due to peak power, so I am not sure
you solve that problem.

if you lower the frequency though, you can more than likely lower the voltage required to
run at that frequency. if you do that, you will use less power.

hope this helps....
 

RU482

Lifer
Apr 9, 2000
12,689
3
81
Yes that helps..thanks!

Curious, how much cooler would a morgan core duron 1Ghz run than an XP1600 with the same HSF?
 

Richardito

Golden Member
Feb 24, 2001
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<< Yes that helps..thanks!

Curious, how much cooler would a morgan core duron 1Ghz run than an XP1600 with the same HSF?
>>



Hmmm. It depends if you are going to overclock or not. I would recommend getting the cheaper Morgan 1.0GHz Duron and properly unlocking it using the pencil trick if you can change the multipliers on the mobo. Even if you can't do this underclocking the XP would be a waste of your $$. Unlocking the XP is more tedious, but not impossible. I've done the procedure...
 

rogue1979

Diamond Member
Mar 14, 2001
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I don't have an XP to compare, but my kids are running a Morgan 1GHz@1209MHz at 1.85v. Golden Gate/27cfm fan, 80mm intake over the cpu and 80mm exhaust. Max temp in Prime 95 42c.
 

Mingon

Diamond Member
Apr 2, 2000
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Looking at the Mobile amd chips that are available on 0.18 micron these are likely to be in the same league as the desktop versions i.e an athlon xp2100 is likely to be the as the athlon 4 1.3ghz. the difference between these is that the athlon 4 runs at 1.4vcore. So with your 1800xp try running it at 1.4-1.5vcore on the 100 fsb and It should hopefully produce a lot less heat
 

mste456

Member
Jun 10, 2001
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yeah the .13 core will be out soon enough. u can actually buy the xp1800 pre unlocked over here in the uk.
from a cooling perspective i use an alpha 8045 with stock fan. my temps rock -
1.4 tbird @ 166/10 = 36&Acirc;ºc
xp1900 @ 1850 = 39&Acirc;ºc

Oh yeah also i use 2 x 120mm ystech fans (135cfm each) one sat right above the hsf blowing out the top of the case and the other blowing directly onto the side of the hsf
as well as the 2 x 120mm phsat fans cooling the gf3
 

RU482

Lifer
Apr 9, 2000
12,689
3
81
I bought a duron 1Ghz from newegg, I'll do a little temperature comparison with the XP1800+