Limiting the MAX fan speed on the MBA via smcFanControl

[Scott6666]

I saw an interesting post today by pgharavi who says he is using SMCFanControl to set the max speed of his fan to 4000RPM:



From the terminal:
/Applications/smcFanControl.app/Contents/Resources/smc -k F0Mx -w 60e0

(that's the default 6200 RPM)

/Applications/smcFanControl.app/Contents/Resources/smc -k F0Mx -w 3e80

(That's 4000 RPM Max)

I obviously gain a few degrees C when limiting to 4000, but at least my MBA shuts up.

Not to question his knowledge but have others tried this and does it really work?

I might not go so far as to set the fan to 4000 (but I might). Given all the thoughts on Coolbook, what do you all know/think about this? Safe and effective relief from fan headaches?

[pgharavi]

http://forums.macrumors.com/showpost.php?p=5266108&postcount=144

I thought about making a thread but I've been too busy. I would suggest changing the topic title to something akin "Limiting the MAX fan speed on the MBA" to get more attention to the specific issue.

Anyway, the app, by itself, will NOT keep your MBA quiet. The GUI purposely doesn't allow you to do this (see the FAQ).

Like I said in the previous topic, you can also increase the max fan speed using terminal.

Thanks for making the topic.

[wgsohn]

Cool. I might try this tonight.

[netddos]

how do we write a script that runs this command during startup and after waking up from sleep?

[sir. mac]

how do we write a script that runs this command during startup and after waking up from sleep?


I thought this was a hack for SMCFanControl, meaning that whenever it runs (as on startup) this fan-limiting script will be active? I haven´t tried it yet, so sorry if this is an embarrassing assumption :)

[pgharavi]

I thoiught this was a hack for SMCFanControl, meaning that whenever it runs (as on startup) this fan-limiting script will be active? I haven´t tried it yet, so sorry if this is an embarrassing assumption :)

I actually don't have the app running at all. It's not necessary for the terminal command.

[sir. mac]

I actually don't have the app running at all. It's not necessary for the terminal command.


That means that you will have to reapply the script in terminal after reboot and wake froom sleep?

[pgharavi]

That means that you will have to reapply the script in terminal after reboot and wake froom sleep?

I made a script and instructed the MBA to run it after boot. I wanted to upload it here but the forum won't let me. It's a simple automator script that auto runs at boot and then closes itself.

If I watch a movie, I just open terminal and enter in the full speed command.

[netddos]

I made a script and instructed the MBA to run it after boot. I wanted to upload it here but the forum won't let me. It's a simple automator script that auto runs at boot and then closes itself.

If I watch a movie, I just open terminal and enter in the full speed command.

do you mind giving us the script for us?

i'm new to mac and have no idea how to run the script automatically..

it isn't like windows where you can just put .bat file under "startup" folder..

[pgharavi]

do you mind giving us the script for us?

i'm new to mac and have no idea how to run the script automatically..

it isn't like windows where you can just put .bat file under "startup" folder..

I didn't know either until like 2 days ago ;)

Just go to Automator, choose custom, and then find terminal or whatever. Then paste in the command from the OP (for 4000 RPM). Then save it as an app, and then put it anywhere you want (I leave mine in Docs).

The final step is to go to your system pref., and then Accounts, Login Items, and then add your little app you just made.

[stakis]

I didn't know either until like 2 days ago ;)

Just go to Automator, choose custom, and then find terminal or whatever. Then paste in the command from the OP (for 4000 RPM). Then save it as an app, and then put it anywhere you want (I leave mine in Docs).

The final step is to go to your system pref., and then Accounts, Login Items, and then add your little app you just made.

hey where in the automator list can you find Terminal... I can't find it anywhere...

thanks

[pgharavi]

hey where in the automator list can you find Terminal... I can't find it anywhere...

thanks

Custom > Utilities > Run Shell Script

That's where you paste the command. Delete the 'cat' text in there first.

:)

[stakis]

Custom > Utilities > Run Shell Script

That's where you paste the command. Delete the 'cat' text in there first.

:)

Works like a charm!! thanks!!!

[msinco]

Thanks on the tip regarding the fan control as well as the automator tip.
After purchasing coolbook, this is exactly what i need.

Instead of putting the automator app at login, i created an automator app that drops the fan to 4000rpm, waits for 10 seconds and returns the setting to default 6200rpm. Im still afraid to set it at 4000rpm all the time. I just need this to tell the macbook air to shut up for awhile. Once it hits 4000 rpm, it usually doesnt go back up and just hovers around 4500rpm.. which is good enough for me.

[stakis]

Thanks on the tip regarding the fan control as well as the automator tip.
After purchasing coolbook, this is exactly what i need.

Instead of putting the automator app at login, i created an automator app that drops the fan to 4000rpm, waits for 10 seconds and returns the setting to default 6200rpm. Im still afraid to set it at 4000rpm all the time. I just need this to tell the macbook air to shut up for awhile. Once it hits 4000 rpm, it usually doesnt go back up and just hovers around 4500rpm.. which is good enough for me.


What a chicken!!!!!

nah , just kidding.... whatever makes you feel comfortable! but don't you notice that when at 6200rpm the CPU is running in the low to mid 60 degrees?? I don't understand this.

[juro]

Don't you guys think that limiting the fan speed is just plain asking for trouble?

The fan is running at that speed to cool the machine off. Sacrificing cooling just to quiet the machine down might toast it.

[pgharavi]

Don't you guys think that limiting the fan speed is just plain asking for trouble?

The fan is running at that speed to cool the machine off. Sacrificing cooling just to quiet the machine down might toast it.

No, it's fine. Like I said, if you are doing wireless productivity, the gain is usually only 1-3 C. Nothing.

Even watching videos the gain is 5 C max. But for that, I would, and do, put the fan back up to 6200.

[MayaTlab]

Hi, I would like to know if I can set the fan up so that they won't rotate over 2500 rpm and not just 4000 rpm. Is it possible ? It seems the command line for 4000 rpm is "3e80". Should I write "2e50" ?

I ask this question because I am very sensitive to noise and really bothered, even at 4000 rpm. And since I have changed the thermal paste and use coolbook I intend to limit the maximum temp at 80 degrees (even if it means that the processor would have to slow down, because the stuff I do on my MBA is not processor intensive).

Thank you for your answer !

[1appleAday]

Hi, I would like to know if I can set the fan up so that they won't rotate over 2500 rpm and not just 4000 rpm. Is it possible ? It seems the command line for 4000 rpm is "3e80". Should I write "2e50" ?

I ask this question because I am very sensitive to noise and really bothered, even at 4000 rpm. And since I have changed the thermal paste and use coolbook I intend to limit the maximum temp at 80 degrees (even if it means that the processor would have to slow down, because the stuff I do on my MBA is not processor intensive).

Thank you for your answer !

So after you reapply thermal paste and use coolbook, the fan speed still high? mind to share the temp and fan speed after you did both? I'm also bothered by fan noise, but if using coolbook and reapply thermal paste (as in your case) still won't make the Air quiet, i may as well give up and live with it. Thanks!

[MayaTlab]

Actually it depends on your usage. You might feel fine if running CPU-only intensive tasks since the fan only turns on when the CPU go over 70 degrees or the heatsink 55 degrees (at least on mine).

Though, if you plan running graphic average intensive tasks (such as a MP4 file), then the fans will turn on quickier because you will be using the integrated chip for Core Image, thus resulting in a superior increase of the heatsink (and not CPU) temp.

This is why I am now able to encode a DVD with Handbrake with very little fan noise but unable to watch the resulting MP4 file without the fans rotating over 4500 rpm !

EDIT : In addition to my previous question, do I have to install SMC fan control even if running the app itself is not necessary ?

[pgharavi]

EDIT : In addition to my previous question, do I have to install SMC fan control even if running the app itself is not necessary ?

I think so. Notice the command references the application. As per your earlier Q, I don't know. there is command (I think it' -h) that will tell you the command for all the...commands...lol)

[1appleAday]

Hi, I would like to know if I can set the fan up so that they won't rotate over 2500 rpm and not just 4000 rpm. Is it possible ? It seems the command line for 4000 rpm is "3e80". Should I write "2e50" ?

I ask this question because I am very sensitive to noise and really bothered, even at 4000 rpm. And since I have changed the thermal paste and use coolbook I intend to limit the maximum temp at 80 degrees (even if it means that the processor would have to slow down, because the stuff I do on my MBA is not processor intensive).

Thank you for your answer !

Did you try limiting the fan speed to 2500 Maya? What's the max temp you've seen after limiting the fan to such low speed?

[pgharavi]

Did you try limiting the fan speed to 2500 Maya? What's the max temp you've seen after limiting the fan to such low speed?

I would imagine that it would be damn high.

[MayaTlab]

Well, I have not been able to determine the hexa code for 2500 so I am currently at 4000 rpm, encoding a DVD with Handbrake. The CPU temp is 76 degrees and the Heatsink 63 degrees. I use CoolBook to throttle down the CPU to keep the temp under 75 degrees, so now my CPU is at 800 mhz, which is fine for me : why would I need handbrake to be faster if I encode during the night ? Moreover, with the fan set at 4000 rpm I can sleep while encoding :).

[pgharavi]

You could email the app creator.

[msinco]

Hi, I would like to know if I can set the fan up so that they won't rotate over 2500 rpm and not just 4000 rpm. Is it possible ? It seems the command line for 4000 rpm is "3e80". Should I write "2e50" ?

I ask this question because I am very sensitive to noise and really bothered, even at 4000 rpm. And since I have changed the thermal paste and use coolbook I intend to limit the maximum temp at 80 degrees (even if it means that the processor would have to slow down, because the stuff I do on my MBA is not processor intensive).

Thank you for your answer !


Use these settings for the ff rpm
6200 - 60e0
5600 - 5780
5000 - 4e20
4800 - 4b00
4000 - 3e80
3600 - 3840
3000 - 2ee0
2500 - 2710

However, I would not set it at 2500. its might just be asking for trouble.

[1appleAday]

Well, I have not been able to determine the hexa code for 2500 so I am currently at 4000 rpm, encoding a DVD with Handbrake. The CPU temp is 76 degrees and the Heatsink 63 degrees. I use CoolBook to throttle down the CPU to keep the temp under 75 degrees, so now my CPU is at 800 mhz, which is fine for me : why would I need handbrake to be faster if I encode during the night ? Moreover, with the fan set at 4000 rpm I can sleep while encoding :).

Thanks for the response. If limiting the fan can push the temp to 75 degrees, i don't think the computer is usable to 2000 rpm? it will either be too hot or you will have to go to 600 mhz or even lower to keep the temp down? as msinco has kindly posted the values for different, i'd be curious of your temp when the fan is set at 2500 rpm max.:D

[MayaTlab]

I will try this soon.

However, I would like to say that, before tweaking my MBA, my CPU temp easily reached 85 degrees while throttling at 800 mhz, with the fan at 6200 rpm (I never had any CPU core shutdown though), so I have not lost any power but gained silence.

Oh and thank you msinco :).

[1appleAday]

I tried the command in OP but it gave me this error:

smc command not found.

anybody knows how to resolve it? i tried both smcFanControl 1.x and 2.x version, tried the command with and without the app running, same result.

thanks for the help in advance!

[fuzzielitlpanda]

bump i have my max fan speed set at 4600RPM. my temperatures never go that high anyways, so there is no need to have 6200RPM as default. The only time I need 6200RPM is when I stress test the machine to ensure stability. However, when I do that, I just boot into windows xp and everything is back on default. This coupled with coolbook has made my mba much more enjoyable.

[MayaTlab]

All right, after a very busy month I have now set the fan at 2500 rpm all the time. Here is my "set up" :

First, I replaced the thermal paste for a bit of Arctic Silver 5 (not the best but I know it well). After calibration, I gained something like 2 to 5 degrees (good enough in my opinion). However, now the heatsink is in direct contact with the CPU and the graphic Chipset (and therefore tends to get slightly warmer than before, but that's a sign of better heat dissipation).

Second, I installed CoolBook. I discarded the 1600 Mhz setting because the CPU used to throttle down before installing CoolBook (to lower the temp) under heavy load. I just kept 800, 1200 and 1400 (setting it to 600 for battery life purpose is unnecessary in my opinion since CoolBook prevent us from lowering the voltage under 0.9v). All of them are set at 0,9v (no kernel panics for the moment). I set the maximum temp at 70 degrees so that CoolBook throttles down if necessary (I never asked to have a powerhouse anyway). The throttling level is set to "high" in order to watch H264 movies without scatters.

And finally I wrote a Script with Automator that launches after login and that set the maximum rpm at 2500. The same script is also used with SleepWatcher so that it also launches after sleep. Finally I wrote two other apps to set the fan at 4000 and 6200 rpm if necessary.

My temps under a very heavy load (Handbrake encode) are : 75 degrees for the CPU (CoolBook seems quite "flexible" and does not strictly respect the set temperature), 68 for the Heatsink.

And I can now "enjoy the silence" :).

[fuzzielitlpanda]

could you run some instances of 'yes' and tell us what your temperatures are as well?

[sir. mac]

And finally I wrote a Script with Automator that launches after login and that set the maximum rpm at 2500. The same script is also used with SleepWatcher so that it also launches after sleep. Finally I wrote two other apps to set the fan at 4000 and 6200 rpm if necessary.
:).

I just downloaded SleepWatcher-package, but could you please post the commands you used to program so that the automator script launches after sleep?

Would be greatly appreciated!! :)

I´ve installed sleepwatcher and sleepwatcherStartupItem, but what to do next? Do I just need to put my automator-scripts in a certain folder?

[Scott6666]

And finally I wrote a Script with Automator that launches after login and that set the maximum rpm at 2500. The same script is also used with SleepWatcher so that it also launches after sleep. Finally I wrote two other apps to set the fan at 4000 and 6200 rpm if necessary.

And I can now "enjoy the silence" :).

Very nice. I assume the scripts are for smcFanControl. You might want to post your scripts to save work for others... TIA.

[sir. mac]

Very nice. I assume the scripts are for smcFanControl. You might want to post your scripts to save work for others... TIA.


That I can do:


Go to Automator choose: custom/shell procedure/ delete "cat"/ insert text below / save as app

6200 max:
/Applications/smcFanControl.app/Contents/Resources/smc -k F0Mx -w 60e0

4000 max:
/Applications/smcFanControl.app/Contents/Resources/smc -k F0Mx -w 3e80

Or one of these speeds

6200 - 60e0
5600 - 5780
5000 - 4e20
4800 - 4b00
4000 - 3e80
3600 - 3840
3000 - 2ee0
2500 - 2710

Go to accounts in settings, and in startup items choose the script-app you´ve saved from automator, choose startup hidden if you like. I´ve put several scripts in a stack on the dock, so I can easily switch between different settings depending on my work scenario. Actually I never need to use 6200RPM-script (as there is very little different between this and 4000 RPM in practice). This gives me almost a noiseless MBA, sweet! :D

[MayaTlab]

SleepWatcher uses Unix executables placed in your Home directory. It is totally different from Automator scripts or Startup items, though the command lines are almost identical (this is why I made a mistake in my previous post by telling you that I "used the same script with SleepWatcher", sorry :)).

I use SMC Fan Control to get to the MacBook Air's SMC settings, so the command line only works with this method. I actually don't use the application itself and the following method is still worth a reading even if you are using a different method to access the SMC settings (you will just have to change the path of the command line).

To create such an executable, open textedit and type :

#!/bin/bash

And on the next line the script you would like to execute.

It gives me :

#!/bin/bash
/Applications/smcFanControl.app/Contents/Resources/smc -k F0Mx -w 2710

Same line as in Automator (to set the maximum fan speed at 2500 rpm).

Then, still in textedit, open the menu "format" and clic on "convert to text file". You should see now a very ugly kind of font (perfectly normal :)).

Save your text in your Home directory (not elsewhere) as ".wakeup" (with the dot but without the quotation marks). You cannot call it differently (that's the way Sleepwatcher works). Because it has been saved with a dot before the actual name, it is considered a hidden file. It is not necessary to reveal it but if you really want to feel secure use a software to reveal hidden files (I personally use Onyx).

Now open the Terminal and type :

chmod +x /Users/YOURHOMEDIRECTORY'SNAME/.wakeup

of course change YOURHOMEDIRECTORY'SNAME into your home directory's name :).

Normally the text file is now a Unix executable and has a totally new and much better looking icon.

Please tell me if there is any mistake here, I'll correct them as soon as possible.

[sir. mac]

Please tell me if there is any mistake here, I'll correct them as soon as possible.

Works like sugar on a plum! Thanks a milliion:D!

But how do I see hidden files in Onyx, you mean using the "find"-app under /utilities?

[MayaTlab]

But how do I see hidden files in Onyx, you mean using the "find"-app under /utilities?


You should go to "preferences", then "finder" and you should see an option to reveal hidden files.

Don't worry Onyx won't mess up with any of your mac (a very neat app ;)).

[sir. mac]

You should go to "preferences", then "finder" and you should see an option to reveal hidden files.

Don't worry Onyx won't mess up with any of your mac (a very neat app ;)).

Thanks! Now all I need to do is reapply the thermal paste (without breaking the machine) and I´m all set for a perfect MBA :cool:

[ozsu]

Well, I have not been able to determine the hexa code for 2500 so I am currently at 4000 rpm, encoding a DVD with Handbrake. The CPU temp is 76 degrees and the Heatsink 63 degrees. I use CoolBook to throttle down the CPU to keep the temp under 75 degrees, so now my CPU is at 800 mhz, which is fine for me : why would I need handbrake to be faster if I encode during the night ? Moreover, with the fan set at 4000 rpm I can sleep while encoding :).

I don't know the code for 2500, but at another blog, someone suggested setting the minimum to 1500. The code for 1500 is F0Mn.

Here is the link to that blog:

http://horstr.blogspot.com/2008/04/dont-throw-your-macbook-air-out-just.html

[ins0mniaque]

I don't know the code for 2500, but at another blog, someone suggested setting the minimum to 1500. The code for 1500 is F0Mn.

Here is the link to that blog:

http://horstr.blogspot.com/2008/04/dont-throw-your-macbook-air-out-just.html

The code for 1500 can't be F0Mn... unless 1500 is that magical numbers that twists reality (it isn't), it's always ( FanSpeed x 4 ) converted to hex, so 1500 is 1770.

[pgharavi]

Either way that seems like a very low speed.

[lonboy]

I have just registered only to thank you everybody for this marvellous sollution. It's good to know that although Apple does nothing useful to solve his customers problems there are people that have clever ideas.

Thank you again and sorry for my bad english
:)

[pgharavi]

I have just registered only to thank you everybody for this marvellous sollution. It's good to know that although Apple does nothing useful to solve his customers problems there are people that have clever ideas.

Thank you again and sorry for my bad english
:)

No problem ;)

[deltaiscain]

I tried to do this on my mbp, but it said it couldn't find the command. Can anyone help please?
Thanks

[superscientific]

Man I feel really stupid but I cannot get this to work. Can someone make a quick video or help me out? I run Automator and follow the instructions. Save it as an app and have in launch at login. I have smcFanControl installed. The fans still run up to full speed when watching Youtube for 5 min +

[chris91]

The script used to work for me before. But not anymore :(
Is it due to a MacOS update or something else ?
Thanks for you help !

[chris91]

UP
Can anyone manage to manually lower speed fan of his MacBook Air since 10.5.5 Mac OS update ?
Thanks !

[pgharavi]

UP
Can anyone manage to manually lower speed fan of his MacBook Air since 10.5.5 Mac OS update ?
Thanks !

yes, my original automator script still works fine. I've attached it here.

[chris91]

yes, my original automator script still works fine. I've attached it here.

Thanks a lot for this pgharavi :)
Unfortunately, your automator script don't run on my MacBook Air :(
When I double-clic on it, I can see very briefly something like a red circle appearing in my menu bar (informing that the script is running) but it has no effect on the rpm when I check in iStat, for example.
It is a complete mystery since this automator script was running very fine before (before what is what I am trying to know).
A few questions :
- Do the smcfancontrol application has to be launched (or launched at startup) to make the script work ?
- Is you smcfancontrol.app at the first level of the application folder (or inside the "smcfancontrol2.1.2" folder) ?
- Would I have to reset smc, pram or something else ?

Any other idea to solve the problem ?

Thanks for your help !!

[lonboy]

The script works fine in my MBA even after the updates though due to some reason I don't know has become unnecesary, now fans work properly going up and down depeding on the work I demand. When I open two videos, fans are at 6200 soon but when I close them fans go down quicklier than ever. Miracle?

[justit]

The script works fine in my MBA
Thanks for finding this. I didn't think to search for such a script. :)

[Surferp]

does anyone know all the different code combo's to get different RPM's via the terminal command with smcFanControl? 4000 is nice but i'd like to go to something like 2500 to 3000 when doing simple web browsing but i don't know the algorith/code at the end of the terminal command. My temp sensor for my hdd is broken so unless i limit it, it will be blazing out of control. new sensor coming soon though.


EDIT: FOUND A SITE WITH THE DIFFERENT RPM COMBO'S HERE: http://iloapp.elvsaas.net/blog/www?Home&post=51

[macchiato2009]

what is the hex for 1000 ?

I want to try putting 1000 for my mac mini late 2009 (fans are currently running at 1500)

thx

[stoconnell]

what is the hex for 1000 ?

I want to try putting 1000 for my mac mini late 2009 (fans are currently running at 1500)

thx

python -c 'print hex(1000)'
0x3e8

[macchiato2009]

python -c 'print hex(1000)'
0x3e8

doesn't work

it has to be 4 digits

i would appreciate if someone can give the value for 1000 and 1500

so ican use the script to set 1000 rpm or 1500 rpm

thx

[johnkimble1]

SMC control doesn't seem to have an effect on any fans on my aluminum imac 20 inch.

I really really need to slow down my fan as I damaged the logic board while carrying out an upgrade (stupid I know) and it means the LCD temp connector doesn't work.

This makes my iMac fan go full speed constantly and it's absolutely deafening - the computer is basically a write off unless I can slow down the fan and I really can't afford a new one.

I found a program called Imac Fan control:
http://www.derman.com/iMac-Fan-Control
it DOES work on my machine for increasing the hard drive fan speed and optical fan speed. Therefore I need to know how to reduce fan speeds using the iMac Fan control app.

I'd really appreciate ANY advice here as any fix is basically going to get me my machine back!

Many thanks for taking the time to read this.

[proboscisjoe]

doesn't work

it has to be 4 digits

i would appreciate if someone can give the value for 1000 and 1500

so ican use the script to set 1000 rpm or 1500 rpm

thx

1100rpm = 1130
1500rpm = 1770

[seelions]

Thx for the great info!

To determine a hex value, take the desired fan speed x 4 then convert it. This can be run in Terminal, replacing "RPM" with the desired speed:
perl -e 'print sprintf("%X", (4*RPM))'
Alternately, you can plug the result of 4 x RPM into this page:
http://www.statman.info/conversions/hexadecimal.html

To determine the fan speed from a hex code, use:
perl -e 'print ((hex "HEXCODE")/4)'
Substituting HEXCODE with either '0x60e0' or just '60e0' will work. Or use the above URL and divide the result by 4.

On a MBA 1.8Ghz, turning the fan down to 2k rpm has the system running cooler, quieter, and on battery gained ~an hour in combo w/ CoolBook!

As they say, YMMV.

[DisTriBution]

I installed smcfancontrol on Lion on a late 2011 MBP (two fans) and ran the command. The left fan was regulated perfectly, but the right fan was not able to be controlled.

So I changed the "F0Mx" in the command line to "F1Mx" and ran that too. In other words, I ran these back to back in terminal:

/Applications/smcFanControl.app/Contents/Resources/smc -k F0Mx -w 3e80
/Applications/smcFanControl.app/Contents/Resources/smc -k F1Mx -w 3e80

Now both the left and the right max fan speed is regulated and my MBP is much, much quieter.

[pgharavi]

Damn this is old!