I have a 1U dual processor rack mount server that is particularly loud even sitting in a closed closet because (as is the case with most 1U rack mount servers) it uses several (4) tiny high speed fans to blow air through the case to keep it cool. Tiny fans like these can move a lot of air but have a habit of creating a loud high pitched whining sound when running and having 4 of them on, in addition to the two CPU fans, can be quite loud. Too loud.
I tried just unplugging the fans and leaving the top cover on but found that it got real hot, real fast. So, I left the top cover off and found that even with the tiny exhaust fans off everything stayed at a reasonable temp but I still wanted to move some air around to keep everything a bit cooler. If nothing else it was an excuse to “make” something.
What I tried was to hang a 120mm (15v) fan above the open server, hoping it would blow cooler air onto and push hot air away from the server. After I had the fan wired up and hung I did some tests to see if the hanging fan did any good:
Operating as designed – cover on, tiny fans running:
CPU1: 84.2°F
CPU2: 87.8°F
MOBO: 101.3°F
Operating with cover off and tiny fans unplugged:
CPU1: 118.4°F
CPU2: 124.7°F
MOBO: 131.0°F
Operating with cover off and hanging fan running:
CPU1: 102.2°F
CPU2: 103.1°F
MOBO: 113.9°F
So the hanging fan does help keep the Opteron processors away from their 156-158°F max operating temperature and it’s much quieter than the 4 tiny fans. It’s certainly not cooling as well as the 4 tiny fans with the cover on but it is acceptable.
What about, you know, unplugging only a couple of the fans? I have a similar 1U server, and it’s loud! I might try this.
@Robert
Even just *one* of the small rack fans is too loud.
I have the same Rackable systems 1U server. All I did was reverse the red 5v lead and the yellow 12v lead on the power plug that goes to the fan backplane unit. it runs the fan unit 60% less. Less power to push the fans. They run quiet now. With the cover on. The CPU’s run 34 to 39 degrees celcius. quiet machine now and it’s awesome. Hope this helps.
@Manny
Sorry for the delay in replying – I was on vacation…
That’s a good idea… my method works out because I am using a secondary hard (not pictured) drive that does not fit in the case with the cover on but I like your method too.
@Manny
I have the same Rackable systems 1U server as you guys do, and I chose to follow Manny’s technique. The fans still run at a decent amount, being 13,000rpm 40mm fans at full 12v, and the noise level is VERY MUCH reduced. I could hear this thing through the entire house, now I can barely hear it in the same room.
@Brad
I actually followed Manny’s advice and did the same… works great!
Soon of later, the CPU is going to burn the motherboard. You need to bring the temperature down a bit lower.
I am having the same noisy problems with two 1U Supermicro severs installed in my living room.
Here is another stupid ideas. Make hole in the top cover the size of the a larger quiet fan. Put the larger quiet fan sitting on top of the hole with the server cover on. Now you can shutdown the noisy fan and problem solved. I don’t have a picture to show you but it works.
@Fritz
Explain to me how that’s a possibility when the CPU is running well within the temperature specs of the processor?
Oh, and posting the same exact comment once is all that’s needed.