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MP 5.1 (2010) noisy fans -replace?

macstatic

macstatic

macrumors 68020
Original poster
Oct 21, 2005
2,029
168
Norway
I find my 2010 Mac Pro 5.1. noisy (I know this is a very subjective matter, but a deep, mid-pitched "propeller plane in the distance" type humming sound is emitted constantly) and am trying to find out where it comes from and what I can do about it.
Using SMC control I believe the "exhaust" fan to be the culprit. Or it may be a combination of several fans. At least the hard drives aren't the cause of this as I checked by unmounting them all using Disk utility.

So which of the several fans is the "exhaust" fan, and is it hard to replace? Having read several postings on the subject I see mention of replacement fans being difficult to source as they should be analog-controlled while the off-the-shelf PC part fans are PWM (digitally) controlled, but I never figured out if this applied to older Mac Pro models or all of them.

Finally, I'm having problems with a fan being "stuck" at a higher speed than before (and yes, I've tried resetting the SMC, but to no avail. Actually all was well when I installed SMC control, but having uninstalled it, then installed Fan control one of the fans started running a lot faster (it sounds like a small fan with its higher pitch -the "PS" fan according to SMC fan control), so I uninstalled it (following the instructions at the author's site above, including resetting SMC) and all seemed well... until installing and running SMC fan control again. It seems like its default settings are higher than the Mac Pro defaults. I believe I saw the fastest fans being at around 800 RPMs according to the iStat pro widget but SMC fan control won't allow the "PCI" and "PS" fans to go bellow 1109. Quitting SMC fan control won't reset things, neither will deleting its preference file.
 
propeller plane

have you tried removing all peripherals & hard-drives inside and cleaning the inside with compressed air ? i had the propeller sound on the intake fan and cleaning it solved it.
 
Yes, I've tried that. I did get some dust removed, but the noise is still there.

What kind of fan/which specifications do I need to look out for?
 
macstatic said:
Yes, I've tried that. I did get some dust removed, but the noise is still there.

What kind of fan/which specifications do I need to look out for?
Click to expand...

You need a direct replacement for the Apple P/N of the fan you are swapping out. The Mac Pro uses proprietary 4-pin fans made by Delta that have analogue speed control (0-12V -> 0-100%) in addition to the usual connectors (+12V, GND, and Tach). No other company makes replacement fans that are compatible with the Mac Pro except Apple.

Some people have had luck hotwiring a standard 3-pin PC fan into the Mac Pro, but I would not recommend this at all. You loose speed control (the fan runs at 100%) and there is the possibility the SMC might try to shut down your system due to an invalid tachometer reading. It sounds like you care about how noisy your system is anyways, so your only real choice is to replace the fan with the proper part number.

-SC
 
I clicked on that link and it went to a comedy club!
Well, it seemed to be a comedy club because they were selling 8800gt's for $691.00!:eek: Now that's funny!:D
 
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Thanks for clearing up the details.
Now I'm not all so sure that it's the exhaust fan after all!

I opened the Mac Pro, then using tissue paper I carefully blocked one fan at a time to hear if there was a difference. It seems that the power supply (PSU) fan might be the cause, and secondly the graphic card fan (ATI Radeon HD-5870), but I don't know if I can access the PSU fan without actually opening it.

So now I'm wondering if the proprietary thing applies to ALL four fans (PCI fan, front processor cage fan, rear processor cage fan and PSU fan)? According to this posting the PSU fan is "standard" although there's no mention of which size/kind/type so I'm taking it with a little grain of salt.

Furthermore the graphic card fan (ATI HD-5870) makes a slight whine as well. I've tried cleaning it with compressed air but it hasn't really made any difference. I'd like to open the plastic enclosure around the circuit board but despite removing screws I haven't been able to succeed. Has anyone here found out how?
 
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OS6-OSX said:
I clicked on that link and it went to a comedy club!
Well, it seemed to be a comedy club because they were selling 8800gt's for $691.00!:eek: Now that's funny!:D
Click to expand...

Not sure what they're thinking but case fans are reasonably priced (for a Mac product)
 
Macstatic - when I removed my 5870 fan to fit a quieter third-party fan assembly I noticed that there were a few smaller than expected screws in odd places which you need to get rid of...

https://forums.macrumors.com/threads/1097022/

STRIP DOWN : After removing the stock 5870, I undid ALL the visible screws on the back side of the card (including those three tiny ones) and the two on the side. The cooler came off easily into two pieces - back-plate and fan assembly. I noted that thermal tape had adhered to the VRM chips.
Click to expand...
 
Nice replacement fan for your ATI graphic card you've got there! They seem to be unavailable though, but I see from your other postings that there are other alternatives. I'll look into those (taking care to find one which won't obstruct the neighboring PCIe slot).

I believe I did remove all screws including the smaller ones but something was still holding the plastic enclosure back. I was guessing one of the chips needed cooling was fastened to parts of the enclosure with heat-conductive paste, and since I don't have any of that I didn't want to risk anything by using force.

I don't know what you mean by the VRM chips but can you confirm that the enclosure is indeed fastened with heat conductive paste in addition to the screws, so if I want to simply open it up to clean it I also need to reapply heat paste?
I thought I'd first try to clean the existing fan, then, if that didn't work I'd look into a fan replacement.

Another thing: reading the Mac performance guide -"4870 Power pig", the standard NVIDIA GT120 is recommended over the ATI 4870 (which I understand is the generation below the 5870) unless doing HD video or gaming because it's noisier and consumes a lot more power.
I'm mostly into photography (Photoshop. Lightroom) in addition to email, web etc of course. I will be doing some video editing later on, but all my footage is standard definition. Would I be better of by selling the graphic card and replacing it with say the GT120?
 
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Yes you will need thermal paste if you remove the cooler - it is cheap and easily available.

When I took out all the screws I could find, the cooler just came off with a little tug. It was a couple of years ago so I can't remember the location of every screw I am afraid.

That cooler that I fitted is no longer available but they do an upgraded one as follows... http://www.arctic.ac/en/p/cooling/discontinued-products/vga/376/accelero-xtreme-plus-ii.html

It will certainly obstruct the second PCI slot as it is a double-height cooler.
 
The most obvious thing to do first is to clean those fans. Really pull them out, disassemble your Mac Pro and just clean them with damp tissue and 1-2 cans of compressed air. I thought I needed new fans until I did that. Took almost 2 hours to clean everything including the heatsink. Haven't had to touch it for 2 years running.

A broken fan with busted bearings won't just make some irritating noise, it'll sound like things are literally breaking. Unless you are hearing that, give cleaning a try before spending money on parts you may not need.
 
CPU B fan not working

Hi, I upgraded processors on my mac pro early 2009 but now cpu fan B is not working anymore.

I clipped the heatsink connector to be able to place the 2 mm higher processors.

And I think by mistake I placed the heatsink connector in the wrong way which I noticed later

I turned it around and placed it back in the right way. But the fan doesn't work anymore.

CPU fan A is going crazy to cool now.

Could it be that I short circuit FAN B?

What could I do to solve this?

Many thanks in advance, feel really bad about this

Thanks, jasper
 
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