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.
{ 16 comments… read them below or add one }
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.
I have a couple of U1 servers in my home office that I need to make silent. I’m going to try Manny’s idea and see if that helps.
Anyone else have any other ideas that work?
@Landmine
Tried it on another 1U server I have and it works well. Just keep an eye on the temp and make sure the room or space it’s in is well ventilated.
Good morning,
I wanted to see how Manny and others that followed switched the wires on the fan backplane. I see the yellow and a black but it leads to the same 12v 5V settings.
My fan backplane looks like its glued in there. Do I need to perform surgery or is this easy. BTW, I’m deploying this server in the a.m so it would be great to receive a response before then so my client does not see me jimmy rigging his server.
Thanks guys,
Chris
Use a multimeter to work out where the 5v is on your power supply. The standard is RED is 5v and YELLOW is 12v, and ORANGE is 3.3v but I’d check.
Should just be a matter of snipping the wires coming from the fan, splicing a Molex connector onto the fan leads (with the appropriate connections being made to the 5v supply) and plugging it in to an available Molex plug. Or, you could splice it directly to a 5v lead from the PS.
I will say that I find it disturbing your going to do this on a clients system. Read the post again and you’ll find that the original modification was for a server I have at home. I’d never do something like this (or lower the fan speed) in a production environment.
Adam,
Thank you for the heads up and don’t worry about my client. He is provided with FREE service and this server is on my dollar. Also he works from home in an upstairs quiet office. So with those factors in place, I’m sure he won’t mind if I perform a minor surgery to his FREE server in order to provide some quietness to his work environment But your overall concern was noted !
Got ya. Just saying – kludges, like the one detailed in the post, and putting the fans on the 5v rail, are acceptable in some situations but not all.
Hi,
Really instead of chopping the wires you should use the SMBus to control the fan speed according to temperatures. Software like SpeedFan can talk to alot of system management chips. The opteron systems are likely to use ADM102x management chip which SpeedFan supports. There is also a SpeedFan service out there so you dont need to keep a user logged on.
Hope this helps.
8buttons
@8buttons
Thanks for the tip – at the time the server was running VMWare ESX so I don’t think that SMBus or anything like it would have worked. It’s still a good tip for those running an OS naively.