Annoyed as I was with the noise from my computer I tried to optimize the cooling of my computer.
I thought it was probably best to guide the air through the case, thereby preventing the contamination of fresh air with used air from the heatsink.
Only recently I found SilentPCreview.com, and here I learned to decouple the harddisk.
Lets have a look.
An overview of my modified rig with the “divided case” system. In the lower right corner the decoupled harddisk, and to the left the cardboard devider that guides used air to the PSU. The rig has only two fans, one in the PSU, and the fan on the heatsink.
AMD Athlon XP 1800+
ASUS A7V333 256 MB RAM ( Raid present, not used )
IBM Deskstar 120 GXP / 120 MB
Coolermaster Al. heatsink with Coolermaster fan ( 70mm x 20 mm)
Nexus NX-3000 PSU.
Pine Nvidia Geforce2 MX400 / 64 MB
Cheap generic case.
Lets have a look at the harddisk first.
I suspended the harddisk from elastic bands hung from the floppy-drive cage.
At the rear there wasn't enough material to support the elastic bands, so wooden sticks fastened with tie-ribs were used to lengthen the support.
4 pairs of holes in the bottom of the case with tie-ribs were used to fasten the elastic down below.
With a heated nail I burned 4 holes on the elastic, and the drive was fastened with it's original screws.
It's a pretty cool place with sufficient airflow there as the drive (IBM 120 GXP-120 MB) typically has a temperature of some 36*C/96*F
Here you see the cardboard divider, separating the used warm air from the cooler air in the case. It is supposed to force the warm air directly to the Nexus PSU to be extracted; and I must say it does it’s job remarkably well.
The graphics-card seals the “hot chamber” at the bottom. To the right the are some, not intended, openings.
Looking up from below you see this.
Again a few openings, but it’s clear that most warm air is being sucked into the PSU.
In an attempt to prevent fresh air from entering the PSU without cooling anything, most
holes above the graphics-card have been closed with adhesive tape.
The heatsink and fan are from CoolerMaster, The fan is a “silent” type (70mm x 20 mm), with 3100 rpm maximum.
Writing this (almost idle) my CPU has 35*C/95*F and the MoBo 29*C/84*F.
Not too bad.
The upper holes in the casing's side are closed with adhesive tape too.
And while we are at it, these gaps above the heatsink-clamp are closed with tape too.
Funny that almost everything I did is in contradiction with the “general advice” on this web-site.
I restricted airflow in a BIG way and didn’t add fans.
I kind off grew fond of modding and tried something else.
What if I could completely seal the air coming from the heatsink, and bring it directly to the PSU.
At http://www.procooling.com/reviews/asset ... banner.jpg
I read that Joe tried several times to reverse the airflow over the heatsink, and the results were not bad at all. Having the fan suck air through the heatsink would make it much easier to capture the used air and bring it directly to the PSU.
This would become the “pull-duct-pull” system. Lets have a look.
The fan on the heatsink has been reversed so it pulls air through the heatsink. With a thin, light foam a duct was fabricated, so it connects directly to the PSU’s intake at the bottom of the PSU. The rear PSU’s intake was (almost) completely closed with a piece of foam in order to prevent the heatsink’s exhaust air from re-entering the case. With some obstructions in between, now both fans are connected in a serial way, thereby offering some redundancy should one of them fail.
In these last two photographs the case is standing upside down to have a better lighting and a better angle.
Noise: Hard to say. I guess about the same or somewhat less.
CPU idle temp: 1-2 degrees C higher, from 35* à 36*-37*
CPU load temp: 3 degrees C lower !!
MoBo temp: 7 degrees C lower, and no rise in temperature under load !!
A game of Warcraft2 with the cardboard divider.
Note how the MoBo temp slowly rises
And here a game of Warcraft2 with the pull-duct-pull system.
MoBo temp doesn’t go up, and CPU-temp is 3 degrees lower!
CPUBurn gives a very heavy load on the CPU, a load not found in day to day computing.
CPU temp after 10 minutes CPUBurn (idle) 70*C/158*F
CPU temp after 10 minutes CPUBurn (normal) 70*C/158*F
CPU temp after 15 minutes CPUBurn (high) 70*C/158*F
These are the three CPUBurn tests.
At the end of the third test the PSU gets warmer and starts revving up.
As said before, this is by no means a totally silent system, it’s a quiet system.
There is still plenty of room for future devellopment.
* I would kill for a few Panafloos (No Panaflo here in Europe !)
* With a panaflo I could dump the heatsinks exhaust-air directly out the rear of the casing.
* Two panafloos pushing air through the PSU would be worth a try too.
Comments are appreciated.