Mac Pro 4,1 Fan noise


Studio K

macrumors 6502
Feb 17, 2013
361
7
United States
Hi, I am having an ongoing problem with fan noise going all the way back to OS X 10.7 - I am now on OS X 10.9. I have tried a few fan apps to adjust fan speeds like iStat, prefpane Fan Control, but none fix the problem. I would like to know if this is a hardware issue I need to look into (i.e. temp sensors) because the noise is becoming very unbearable.

Temp readings for those wondering are CPU A TDiode - 122˚; CPU B TDiode 108˚

Thank you
Which fans are too loud? IStat will display the speed for each fan. I'd be curious to see what iStat is showing.
 

Studio K

macrumors 6502
Feb 17, 2013
361
7
United States
It is one of the front fans, it sounds like the one next to the GPU. I can write down what iStat displays:

Booster 1 - 2497rpm
Booster 2 - 2497rpm
Exhaust - 956rpm
Expansion Slots - 1202rpm
Intake - 957rpm
Power Supply 748rpm
They all appear to be going faster than normal. But it's the Booster fans that are really going fast.
Intake and Exhaust are only modestly faster than normal and would not be audible at 957rpm.
Expansion is about 400rpm above normal but still not fast enough to be very noisy.
The Booster fans would be kind of noisy at 2500rpm. They would normally be running at 1100 each.

How long has it been like this? Did you ever bring it to Apple?
 

Studio K

macrumors 6502
Feb 17, 2013
361
7
United States
I o

I did an SMC and PRAM reset just a couple hours ago. Reading now are:

Booster 1 - 3764rpm
Booster 2 - 3762rpm
Exhaust - 671rpm
Expansion Slots - 1229rpm
Intake - 671rpm
Power Supply 764rpm

Temperatures:
CPU A 133˚F/56˚C
CPU B 116˚F/45˚C
Those fan speeds are quite strange. Who would have thought an SMC reset would make the Booster fans speed up even more???

The Booster fans are mounted inside each cpu heat sink. They are more insulated than the other fans and are, therefore, harder to hear. But at those rpms, they would be kind of noisy.

I just cannot imagine what's causing those CPU fans to spin so fast. Perhaps you could pull the CPU tray and remove the heatsinks just to have a look around under there. Mabye put some new thermal paste on the processors.
Probably won't fix the problem, but it's worth a look.

I guess this all started after Apple Care expired? Bringing to Apple would be your best bet, I think.
 

Macsonic

macrumors 65816
Sep 6, 2009
1,473
17
Earth
Thanks for the reply. I clean the system about 2x a year, I have yet to change the thermal paste. I could be mistaken, but the noise seems to be coming form the the GPU. I am trying to see if others have had similar problems with the 4870.

I'm not exactly sure when the problem started but I've noticed it more in the past 12 months. I always attributed it to just the load from multi-tasking in multiple programs, but it is noisy even with just a browser open.
Sorry to hear about your fan speed problem. Though this may not be the solution, you can try a SMC Reset http://support.apple.com/kb/ht3964

A second option is a Hardware Reset which you will disassemble all the internal parts and place them back in so as to reset everything.
 

h9826790

macrumors G5
Apr 3, 2014
12,800
5,622
Hong Kong
The 4870 indeed is very noisy when loaded.

Anyway, did you ever try to do a clean OSX install? It may fix the CPU fan problem.

Also, I've experienced quite a few times that high fan speed after SMC reset. Don't know the reason. My fix is

1) Open smcFanControl
2) set all the fan to 100%
3) wait for about 10 seconds
4) set it back to default

The fans may need few minutes to slowly get back to the normal speed. This usually able to fix the problem. No need to do another SMC + PRAM reset.

If the graphic card fan speed too high without any loading. Run LuxMark benchmark once usually able to fix the problem.

But these work around only works if there is no real loading to the CPU / GPU. If there is some software issue (e.g. kernel task keep running at 100%), the CPU fan of course will run high to protect the CPU and try to cool it down. You may check the Energy tap in activity monitor to see if there is anything loaded up your Mac, and cause the CPU hotter than normal.
 
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ofawx

macrumors newbie
Sep 26, 2013
12
0
UPDATE
... Could the card be defective? Is this an issue others have had with the 4870? The card performs well- just the fan noise is becoming unbearable.
I used to run a 4870, and as others have said, it is very loud under load. That said, when not stressed, it was no louder than any other fan.

One possibility worth considering, depending on your 4870's history, could be failure of some sort.

After 4 years of service mine became increasingly loud over a period of weeks, even at idle. Despite being fairly clean, I cleaned the dust out, to no avail, which led me suspect a mechanical failure of some sort in the actual GPU fan (sound became less 'fan'-like, more mechanical grinding. Bearings perhaps?)

I elected to replace the whole GPU as it didn't make sense to me to put money into a 5 year old GPU, but if you've got parts available replacing the fan could be an option.
 

GHelf

macrumors newbie
Jan 1, 2012
5
0
Hello,

I have a 12 core Mac Pro with fans also running fast. Does anyone know if there is a reference for how fast fans are supposes to be running at idle (start up, no apps running) for 12 2.93ghz, 5.1 mac pro?

Thanks.
 

h9826790

macrumors G5
Apr 3, 2014
12,800
5,622
Hong Kong
Hello,

I have a 12 core Mac Pro with fans also running fast. Does anyone know if there is a reference for how fast fans are supposes to be running at idle (start up, no apps running) for 12 2.93ghz, 5.1 mac pro?

Thanks.
In my Hex Mac Pro, the idle RPM is 600 for most of the fan, and the booster fan is around 900RPM.
 

GHelf

macrumors newbie
Jan 1, 2012
5
0
Thanks. All my fans were around 1000 rpm and boost fans were up around 1900.

Still under applecare. Brought it into Apple store. They are running further tests. They were really cagey when I asked what the exact rpm's for the box should be and would not provide an exact number, only that mine seemed a little high. I got the impression that if nothing turns up on a test, I am on my own.
 

mikeboss

macrumors 65816
Aug 13, 2009
1,274
451
switzerland
hex 3.46 GHz idling

Booster Fan CPU A: 850 RPM
Exhaust Fan: 600 RPM
Fan Expansion Slots: 800 RPM
Intake Fan: 600 RPM
Power Supply Fan: 600 RPM

all five fans running at their specified lower limit, except Booster Fan which has a lower limit of 800 RPM.
 

GHelf

macrumors newbie
Jan 1, 2012
5
0
mikeboss,

is your machine a 6 core or a 12 core, and, how can I find what the specified lower limits are for each fan on my machine?

thanks.
 

h9826790

macrumors G5
Apr 3, 2014
12,800
5,622
Hong Kong
mikeboss,

is your machine a 6 core or a 12 core, and, how can I find what the specified lower limits are for each fan on my machine?

thanks.
You can simply install SMC fan control, and read the default fan lower limit from it's default fan profile setting.
 

Plutonius

macrumors 604
Feb 22, 2003
7,855
6,018
New Hampshire, USA
Doing a search, it looks like the ATI 4870 can get very hot and loud when under loading conditions. The recent versions of OS X puts much more stress on the GPU then older versions.
 

Emen Mali

macrumors newbie
Jul 22, 2014
26
1
Chicago, Illinois
I just upgraded my Mac Pro 2009, from the original 8x2.26 to 12x3.33, while I was "in there" I upgraded the Airport to AC and BT 4.0, 5870 to 7950. The only problem I have is Booster 1 (Fan I assume) is 0rpm, the fans are revving pretty high and this is at 0. I'm currently using Macs Control Fan to bring the noise down and have set 2 fans (intake and exhaust) to Ambient.
Is Booster1 the CPU A heatsink fan? Anyone I can tell if its likely to be damaged?
 

TzunamiOSX

macrumors 6502
Oct 4, 2009
301
47
Germany
I just upgraded my Mac Pro 2009, from the original 8x2.26 to 12x3.33, while I was "in there" I upgraded the Airport to AC and BT 4.0, 5870 to 7950. The only problem I have is Booster 1 (Fan I assume) is 0rpm, the fans are revving pretty high and this is at 0. I'm currently using Macs Control Fan to bring the noise down and have set 2 fans (intake and exhaust) to Ambient.
Is Booster1 the CPU A heatsink fan? Anyone I can tell if its likely to be damaged?
https://web.archive.org/web/20131026053641/http://pindelski.org/Photography/2013/07/08/mac-pro-2009-part-tbd/

and pictures
http://puier.lofter.com/post/80c4b_6a8195

Booster is a fan inside the cooler (main cpu cooler). CPU A is the rear CPU. I think your fan connector has no contact.

If one fan don't work, it is not very intelligent to use Software like Macs Control Fan and ignore the problem. You will destroy your CPU by overheating.

SOLVE THE PROBLEM that you caused by your bad tech skills!
 
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