[Success @ 1.2ghz] Underclocking XP-M and passive

metalac · Post by **metalac** » Mon Jun 13, 2005 9:39 pm

Hey guys,

I've got an XP-M (35W version) on Abit NF7-S v2.0. Currently being cooled with a slow spining 80mm fan and SI-97. Now I've got it underclocked to 1.2v and 1200mhz. There is no other case fans and the temperatures I'm geting are:

cpu:43C
amb: 32C

These are both under load, I've been compiling something for about an hour and would hate to stop it now to check the idle temps

. What I was wondering is what could I expect with totally passive system? Will I hit 50C? or should I be expecting something much higher? I'd like to try, but wouldn't want to fry the CPU. If anybody has any similar experiences please share. I would really like this thing to go passive since the case I'm building there is really no room for an extra fan although the heatsink will be exposed to the "outside" since there will be fairly large grill right above it.

p.s.
by some calculations the CPU is puting out 18W of heat, which is pretty low I'd say.

metalac · Post by **metalac** » Tue Jun 14, 2005 6:44 am

Well I was sooo eager to try this, and I couldn't wait for any reply and here it is:

IDLE

cpu:46C
amb:38C

LOAD (after half an hour or so of compiling stuff)

cpu:55C
amb:43C

This is on the cpu running 1200mhz and 1.2V with NO fans inside the case, except the power supply fan, but that thing is far away that I can assume that this computer will work just fine on a totaly fanless system, especially if I use that PW-200M power supply that outputs very little

perplex · Post by **perplex** » Tue Jun 14, 2005 7:11 am

nice result. but next try that prime95 program

metalac · Post by **metalac** » Tue Jun 14, 2005 7:32 am

I run linux and I'm not sure if there is prime95 for it, but I can tell you that I've been compiling something for the past hour and temps are at:

cpu:54
amb:43

Compiling does tax the system quite a bit. CPU usage is at 100% while it's compiling and the HD is churning up every once in a while.

Next step will be to try and get it to boot at lower voltage, I already know that 1.1V will not work, so I will try 1.15V.

metalac · Post by **metalac** » Tue Jun 14, 2005 3:09 pm

another update.

I went to work and I left a computer on since basically 6:30 this morning. I got up at 6:30 turned everything on with no fans. Did some compiling and got the results show above. Came back to the board and saw the prime95 suggestion. Found linux version for it "mprime" and ran it for about half hour or so and got following results:

cpu: 56.5C
amb: 44C

It seemed to plateu around 56.5C I didn't see it go above but did see it go down to 56C a few times.

After this I shut off mprime and left for work. I just got in ad it's about 6-7 hours later and I got the following results on idle:

cpu: 49C
amb: 41C

I'll run mprime for another hour and see what happens. Will post the update.

GameManK · Post by **GameManK** » Tue Jun 14, 2005 5:16 pm

when i tried something similar, when i turned the CPU fan off it seemed fine and the temp stayed below 55 degrees, but then the computer just restarted before a half hour

but if it worked for you, congrats

metalac · Post by **metalac** » Tue Jun 14, 2005 7:18 pm

Well here is an update.

Once again I ran "mprime" for approximately an hour and here is what i got:

cpu: 56.5C
amb: 45C

Now I might also add that my room is a toasty 29C even though the weatherman says its 17C outside.

After I finished the mprime test I left house for about 3 hours or so and when I came back I found the computer idle running as:

cpu: 48.5C
amb: 41C

So I'm glad to let everyone know that SI-97 with a Athlon XP-mobile at 1200Mhz and 1.2V will run just fine.

Now I'll turn the fans back on since my HD is geting little toasty and the heatsink I'm building for it still in the works, more about that later.