Quiet cooling and distributed computing

Zyzzyx · Post by **Zyzzyx** » Wed Jan 01, 2003 2:10 am

So I got to wondering... (dangerous, I know)

How many folks out there have some nice quiet systems, and also run distributed computing programs? (SETI@Home, Folding@Home, Prime95 ?, etc) Pondering how well quiet cooling works with continuous 24/7 100% CPU load.

Zyzzyx
- still not quite willing to give up SETI, but pondering Folding instead

Post by **Ralf Hutter** » Wed Jan 01, 2003 7:44 am

The PIII-S server rig in my sig runs Prime95 at 44-45C. Just ran 24hrs worth yesterday. This box is damn close to inaudible. You can't hear it at all during the daytime (with normal household background noises) and at night when it's real quiet you can just barely hear the air whoosh of the 5-volted Panaflo case fan. I think even the most hard-core quiet freak could live with this doing SETI.

Prior to this I was running an OCed 1.1A Tualeron in this exact same box. It was running 2-3C hotter under Prime95 load.

Cost of PIII-S 1.4 is $208, cost of a 1.1A Celeron is $41.

Post by **NeilBlanchard** » Wed Jan 01, 2003 8:27 am

How many folks out there have some nice quiet systems, and also run distributed computing programs? (SETI@Home, Folding@Home, Prime95 ?, etc) Pondering how well quiet cooling works with continuous 24/7 100% CPU load.

Right off the bat, let me qualify my response by saying my machine is not quiet. It is a lot quieter than it used to be, but quiet it ain't. It started life as an IBM Aptiva Athlon 600 (now known as "Classic) and I have upgraded it to a 700mHz with another Slot A processor. I have an aftermarket HS with 2 Stealth 60mm undervolted to 5 volts.

The PS was a 200 watt, but it now has an Enlight 350watt with thermally controlled fan and I've moved the thermistor so that it doesn't touch the internal HS directly to keep it running slower. I've also bent (by using a sophisticated technique with my needlenose pliers) the grill so that the edges of the sheet metal are in the airflow. I also twisted the metal between all the intake slots on the PS to 90d to improve the air flow, as well. This gave a huge improvement in both air flow and quieter operation. I briefly tried an Antec fan, but it got noisy after a few weeks -- bearing slop caused the fan to get into a mode with a lot of vibration. The stock fan is a bit noiser than the Antec was at the start, but it doen't vibrate.

I have a 92mm Antec SmartFan as the intake, and the metal grill was snipped out and I have a wire grill installed. This fan runs quite a bit slower than maximum since the room air temperature is about 68F. On the case exhaust, I have a slot-mounted fan, similar to the Antec, but it uses an impeller with a lot (50-60) curved vanes. This is also undervolted to 5 volts.

The loudest noise is the 40GB 7200RPM Western Digital HD. To diminish the whine, I have stuffed four pieces of corrugated cardboard under both sides of the case. This helps, but only by a dB or 2. You can also hear a low rush of air and fan bearings, but the whine is dominant. I was going for good cooling (and I have it) and since have been able to quiet it by about 40-50% by undervolting and tweaking. Let me put it this way: before I did not even hear the HD, and I now have to try to hear the whole machine -- from the next room!

However, it is still too loud, as the Antec cased machine with very similar specs that I built for my sister ran at least 50% quieter than this machine. That machine had (3) 80mm case fans (undervolted through the Antec PS) along with the (2) 60mm on the HS. It had (2) 5400RPM hard drives, and the hard drive seek noise was by far the loudest thing. The Antec cased Athlon 550 was as noisy from 1.5 feet away as the IBM is from 6-7 feet.

SO, yes I do run SETI@Home 24/5 (weekdays) and Genome@Home 24/2 (weekends) and things are quite cool, though I can't give you any hard numbers -- gotta luv those OEM motherboards! I was running the same on my sister's machine before I gave it to her -- it ran for 2 months without one crash!

The Antec 330watt PS in my sister's machine ran much warmer than my machine's Enlight PS, though this may be due to my fan running a bit faster. The case air temp was cooler on her's, though.

BTW, I have processed 2,436 SETI work units since May 22, 1999 which was just 4 days after the SETI project started. I have a total of 2.915 years of CPU time during that 3.618 years! My average processing time is 10 hours 28 minutes 56.4 seconds.

http://setiathome.ssl.berkeley.edu/fcgi ... _stats_new

For Genome@Home, I've processed 512 genes since May 19, 2001

http://genomeathome.stanford.edu/cgi-bi ... _Blanchard

Red Dawn · Post by **Red Dawn** » Wed Jan 01, 2003 9:13 am

Say, you wouldn't have that 600 mhz Athlon (or was it a 550?) Slot A cpu for sale, would you?

I would be interested in buying it if the price is right.

PM me or something if you still have it lying around, and if you are willing to sell it.

SungHyun7 · Post by **SungHyun7** » Thu Jan 02, 2003 9:08 am

hey ralf, my pIII type-R is also quite silent

(what's pIII-S anyway? tualatin? hehe my bad, just couldn't help it) i've ran prime 95 (100% load) for 3 days in one weekend straight when i was staying over at my parents' place and ran into no problems at all. same result for 3dmark SE demo. ran it overnight + my normal 8hr shift and some more with no problem at all.

the real issue at hand is the future reliability of these computer (if that). not necessarily the fear of any heat overload. but the question is, will you have your computer 7-10 yrs from now? even then, i would think these would work fine.

my set up:
p3 1ghz fc-pgaII cooled with zalman 6000cu with fanmate turned ALLLLL the way down.
zalman psu with panaflo @ 5v.
radeon 9000 (non-pro) 128mb made by sapphire.
wd1200jb special edition drive in smart drive (i got smart drive after i ran all those tests, but result should be the same).