Cooling densly packed servers

[Zyndram]

Hello,

At my work there are 120 1U servers, based on a mini-itx motherboard, equipped with 3 hard drives and an ssd, and an Intel Atom processor. When the casing is open, and the computers are installed in every second slot in the rack, all is well and the CPU works fine even with the fan removed, with only the radiator. However if I install the computers tightly, 40 per rack, the heat is so great the processors shut down. I tried rearranging the components a bit, but it does little help. Could you please recommend some small but strong fans or cooling techniques to increase the airflow thru the casing? Attached are a couple of photos of the computers. Thanks in advance for any help.

 

[ATMINSIDE]

Typically for something like that you need an AC unit just for that room, and have that room sealed off.

 

[Zyndram]

There is AC. There is lots of other hardware in that room, everything else works fine.

 

[Automata]

Hello Zyndram, do you know what the intake and exhaust temperatures of the case are? From your description and from the pictures, it looks like those two 40mm fans are not enough cooling for the case. As long as the processor is making good contact with the heatsink, not enough airflow through the case will manifest as having much higher exhaust temperatures, compared to intake.

If that is what you see, some Delta or Panaflo fans should take care of the issue.

 

[Zyndram]

I should have added this to my original post, the radiator+fan on the cpu are around 2-5mm from the upper case. I'd like to replace those with some sort of horizontal fan + radiator, however it seems space is my biggest constraint.

Thank you thideras, I'll make some measurements tomorrow.

 

[Automata]

That could certainly be a problem and fixing it may prove interesting. Normally in 1u-3u servers, they will have plastic pieces that force air over the CPU heatsink and the motherboard as fans generally won't fit and it is easier/better to just let the case fans handle it. With that type of mounting system, I really doubt you are going to find a heatsink that will have the fan orientation you want.

However, with enough case flow force in the right direction, cooling those processors should be easy. Atom processors don't put out a lot of heat, so they aren't going to need a lot of cooling. I'd try upgrading the fans (also, put in more than the two if you can) and then remove the CPU fan to see if that helps.

 

[wagex]

you could probably run the cpu passive if you were to get higher speed case fans. the two 40mm fans in the middle of the case that thideras mentioned.

something powerful like these panaflows
http://www.performance-pcs.com/cata...oduct_info&cPath=36_1127_123&products_id=4544

or if you are feeling real crazy find some 12,000 rpm fans.

 

[Zyndram]

Hey wagex, I have some doubts about the fan you suggested after reading the sticky thread with introduction to fans. The wings are not dense, and it says "low sound" in the description. As you see, my systems are densely packed, with disks, cables and memories blocking the air flow. I understand that what I should try to do is install four high static-pressure fans in parallel on that metal scaffold in the middle. Are you sure the fan you mentioned will do? Noise is not an issue.

Is something like this worth trying, in this small case scenario?

 

[Automata]

Those are complete garbage. They use crap bearings in them, so they fail extremely fast. They also push next to nothing for air.

 

[wagex]

the fans i linked are 9500 rpm at 45db dont think that is very quiet lol. and pretty fast. check the label on the fans in there and post the model number here.

 

[TiZakit]

The way I see it, you really have three options.

Find a way to force more air into the case; - Better fans. Are there any fans on the front of those 1U servers at all? I can't tell from the pictures (Wait, I just saw the mid line fans, do they have any way to get air? Is there anywhere for it to go?)
Find a way to rotate the motherboard so air can flow though easier.
Drastically lower the room temperature.

If you have no intake fans, I'd start there, and look towards motherboard rotation.

If you have cash to spend on the problem, you could look at something like a Liebert MCR. http://mainlinecomputer.com/products/liebert-foundation-mcr-42u-complete-with-a-slash-c

 

[kyfire]

Could you add these to the rack? http://www.dsiwholesalers.com/item.cfm?id=188

 

[Automata]

Could you add these to the rack? DSI 1u Four Piece Rack Mountable High Power Fan Tray - 1000cfm

What is that going to do? The fans aren't even facing the right direction.

 

[kyfire]

What is that going to do? The fans aren't even facing the right direction.

My understanding of these is to circulate high amount of air through a server rack.

 

[Automata]

My understanding of these is to circulate high amount of air through a server rack.

That is going to do nothing when the problem is airflow through the chassis and when the fans don't point he correct direction.

 

[NiHaoMike]

It looks like the heatsinks have the fins facing the wrong way to take advantage of airflow.

 

[kyfire]

That is going to do nothing when the problem is airflow through the chassis and when the fans don't point he correct direction.

If these offer no cooling effect. Then what is the purpose of them being sold?

 

[Automata]

If these offer no cooling effect. Then what is the purpose of them being sold?

I'm sure someone could find a use, but I can't think of one. Rack flow generally goes front/back, back/front, or (less common) side/side.

 

[kyfire]

I'm sure someone could find a use, but I can't think of one. Rack flow generally goes front/back, back/front, or (less common) side/side.

Good answer!

 

[cullam3n]

Every 1U I have seen in production has blower-style coolers. They are loud as hell but they do move a lot of air.



In your case, you really need more fans to pull air through the front and out the back. Also you say they are getting cold air in the front, but how is the rack cooled? Is it open or enclosed? Are you following the hot/cold aisle separation? Is the front or rear doors mesh/grille or does it have a plexi front? Are their fans on top or in the rear of the rack?