Yosemite and CPU fan speeds

Thomaspin · Oct 21, 2014

Both charts are for dual X5675 3.06GHz Westmeres running Geekbench2 stress test (more demanding than the one in GB3) with all cores loaded in an upgraded 2009 Mac Pro.

No fan control utility used in either.

Mavericks 10.9.4:

Yosemite 10.10.0

Some comments here have stated that the Mac Pro's fans are quieter in Yosemite than with its predecessors. In the above, Mavericks was running the CPU fans at 3,200rpm compared with 2,200rpm in Yosemite, explaining the large jump in CPU temperatures in Yosemite.

The service limit for the X5675 is 178F (with Yosemite CPU A reached 151F - almost 40F warmer than in Mavericks) so if I was doing demanding video renders all day long, I would seriously consider using a fan control utility to speed up the CPU fans. On removal, after one hour of the stress test in Yosemite, the Processor tray/heat sink assembly was very warm to the touch, almost uncomfortably so.

Data are much the same over many machines and many tests. Best quality thermal paste was used.

h9826790 · Oct 21, 2014

For your info. Without any fan control software, my 4,1 will run my W3690 to 185F (85C) with idle fan speed. And then only speed up a little bit to keep it at 185F. The native fan control logic seem no change from Mavericks to Yosemite.

I've keep this config for quite a long time, and never have any thermal warning in the thermal log.

lexR · Oct 21, 2014

I've had the same temp changes since the first beta version of yosemite and It freaked me out for a while thinking my SMC was faulty but so many people reported it I just download SMC fan control which auto starts on boot and set some presets as a cool CPU is a happy CPU

maclove4life · Oct 21, 2014

h9826790 said:
For your info. Without any fan control software, my 4,1 will run my W3690 to 185F (85C) with idle fan speed. And then only speed up a little bit to keep it at 185F. The native fan control logic seem no change from Mavericks to Yosemite.

I've keep this config for quite a long time, and never have any thermal warning in the thermal log.

I have 4,1 as well..but i seriously don't know what the heck you guys talking about...i just happened to run into this thread....would i also need fan control? isn't there native one?

h9826790 · Oct 21, 2014

In general, no. Your computer will work fine without any fan control software. However, it's design to run the CPU at max temperature (when fully loaded) in order to keep the fan noise at minimum. So, if you don't like this setting, you can install some other fan control software to make your own thermal setting (e.g. lower temperature but more noise).

Sharky II · Oct 21, 2014

I have a 2009 Mac Pro flashed to 5,1 and running a 3690 (10.9.5)

The cpu fan at default is nowhere near those speeds though, it's 855 for the boosta fan (mainly because the 600rpm of the exhaust fan creates a vacuum and speeds up the cpu boosta fan by sucking the air through).

The other fans run at 600 or 800rpm by default.

Can you guys clarify what you mean?

maclove4life · Oct 21, 2014

h9826790 said:
In general, no. Your computer will work fine without any fan control software. However, it's design to run the CPU at max temperature (when fully loaded) in order to keep the fan noise at minimum. So, if you don't like this setting, you can install some other fan control software to make your own thermal setting (e.g. lower temperature but more noise).

Thank you so much for this explaination...i was worried for a second there...
Where can i download 4,1 version of this fan control thing?

h9826790 · Oct 22, 2014

Sharky II said:
The cpu fan at default is nowhere near those speeds though, it's 855 for the boosta fan (mainly because the 600rpm of the exhaust fan creates a vacuum and speeds up the cpu boosta fan by sucking the air through).

The other fans run at 600 or 800rpm by default.

This is completely normal. Exactly the same as my 4,1.

h9826790 · Oct 22, 2014

maclove4life said:
Thank you so much for this explaination...i was worried for a second there...
Where can i download 4,1 version of this fan control thing?

There are few fan control software available. e.g. Mac Fan Control, SMC Fan Control, etc.

And I personally prefer this one. You can simply adjust the threshold temperature in system preferences to setup your own fan profile. e.g. If you move all the slider to the max position. It will roughly give you max CPU temp between 70-75C (ambient around 35C), and won't speed up the fan until your CPU above 60C.

On top of that, you can also increase the min booster fan speed to something like 900RPM to cool down the north bridge for few degrees with virtually no fan noise increment when idle.

Sharky II · Oct 22, 2014

h9826790 said:
This is completely normal. Exactly the same as my 4,1.

Sure, thanks - but are they lower/quieter in Yosemite?

Cheers

Ed

maclove4life · Oct 22, 2014

how do i even install these? confusing...i'm noob..when it comes to this.

h9826790 · Oct 22, 2014

1) Unzip the file, then you will have a folder that contain 4 files.

2) open Terminal

3) Type "cd " (with space) then drag the folder (which contain that 4 files) to terminal

4) Hit Enter

5) type "sudo " (with space) then drag the file "install.sh" to terminal

6) Hit Enter

Enter password if required. And then check your system preference and choose Fan control. You will see something like this.

You may then setup your own fan profile.

minifridge1138 · Oct 22, 2014

Thomaspin said:
Both charts are for dual X5675 3.06GHz Westmeres running Geekbench2 stress test (more demanding than the one in GB3) with all cores loaded in an upgraded 2009 Mac Pro.

No fan control utility used in either.

Mavericks 10.9.4:

Image

Yosemite 10.10.0

Image

Some comments here have stated that the Mac Pro's fans are quieter in Yosemite than with its predecessors. In the above, Mavericks was running the CPU fans at 3,200rpm compared with 2,200rpm in Yosemite, explaining the large jump in CPU temperatures in Yosemite.

The service limit for the X5675 is 178F (with Yosemite CPU A reached 151F - almost 40F warmer than in Mavericks) so if I was doing demanding video renders all day long, I would seriously consider using a fan control utility to speed up the CPU fans. On removal, after one hour of the stress test in Yosemite, the Processor tray/heat sink assembly was very warm to the touch, almost uncomfortably so.

Data are much the same over many machines and many tests. Best quality thermal paste was used.

What did you use to generate those graphs?

h9826790 · Oct 22, 2014

Hardware Monitor

maclove4life · Oct 22, 2014

h9826790 said:
1) unzip the file, then you will have a folder that contain 4 files.

2) open terminal

3) type "cd " (with space) then drag the folder (which contain that 4 files) to terminal

4) hit enter

5) type "sudo " (with space) then drag the file "install.sh" to terminal

6) hit enter

enter password if required. And then check your system preference and choose fan control. You will see something like this.
View attachment 507549

you may then setup your own fan profile.

thanks!!

DPUser · Oct 23, 2014

I, too, use a fan utility to keep the Northbridge chip running a little cooler. Peace of mind. Mr. Pindelski gets the credit from me on that point.

Denis Ahrens · Oct 23, 2014

Hi

There is one step missing.

6) Doubleclick on the FanControl.prefpane

Denis

hotdog4u · Oct 23, 2014

h9826790 said:
1) Unzip the file, then you will have a folder that contain 4 files.

2) open Terminal

3) Type "cd " (with space) then drag the folder (which contain that 4 files) to terminal

4) Hit Enter

5) type "sudo " (with space) then drag the file "install.sh" to terminal

6) Hit Enter

Enter password if required. And then check your system preference and choose Fan control. You will see something like this.
View attachment 507549

You may then setup your own fan profile.

thanks!

----------

Denis Ahrens said:
Hi

There is one step missing.

6) Doubleclick on the FanControl.prefpane

Denis

at what part?

Sharky II · Oct 23, 2014

FWIW i've installed Yosemite and fan speeds are exactly the same. Using iStat to monitor.

It's idling slightly cooler, however that could just be due to colder ambient temps for all i know

h9826790 · Oct 24, 2014

hotdog4u said:
at what part?

That should be Step 7

GraniteTheWolf · Oct 26, 2014

on my 2012 6-core.

Stock fan speeds had my booster fan set to 600rpms, causing my IOH Tdiode (northbridge) to idle around 71C and when in heavy use get near 80C.

Using iStat I bumped the booster fan up to 980 rpms minimum speed and now it hardly goes above 60*C and it also brought down my cpu temps a little as well.

Yosemite and CPU fan speeds

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