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ward m · May 14, 2005, 08:42 PM

Greetings All,

Does anybody know of any apps, utilities, or applescripts that allow manual control of a G5's fans? I'd like to be able to control the fan speeds manually, and automatically through applescript, etc. I haven't found anything useful yet.

I'd like to be able to:

- create a shutdown routine that idles the processors, runs all the fans a full speed for a couple of minutes (user selectable time), and then shuts down the computer. Don't like to ride it hard and put it up wet..er, hot.

- adjust Apples fan speeds heat curves to allow faster fan speeds than normal, to keep things cooler. Noise is less important sometimes. The fans in my new G5 Dual 2GHz (2nd gen) run very slowly, just barely turning most of the time. Runs hotter than I'd like.

- have the capability to reset the fan speed curves to Apple factory default.

My imagined GUI for this app/utility would be a side shot of an open G5, or similar stylize pic showing the internal fans that can be clicked on individually (or in sets where appropriate) to access both predefined scripts and user configured scripts, with the ability to reset individual fans and all fans globally to factory heat/speed curves.

Extra credit:
Might be nice to get some kind of temperature feedback status using some of the system's heat sensors, to allow monitoring temperatures of components and fine tuning of fan speeds.

Does such a magical app exist, or is it possible to control individual fan speeds through applescript?

Thanks!

Xophonic · May 24, 2005, 05:45 AM

I too have combed the net for any such app to no avail. The only tips I've found was one individual physically relocated a few of the sensor in his g5 to locations he beleived were more accurate to the temparature of the components. one of particular concern is the fan in the hard drive bay. the sensor is sandwiched between the roof of the case and the drive mount. in this spot it comes in contact with the case which is made of conductive aluminum and is much much cooler than the drives themselves. he suggested moving the sensor closer to the drives to give the mac a more accurate read of its temparature. but this seems excessive and unneccesary.
apple should release an app like you described. Please let me know is you or anyone else has a better solution.

[email protected]

d.fine · May 24, 2005, 05:54 AM

Would be nice, thought I wouldn't use it. Slow turning fans mean that the CPU is operating within normal temperatures. Making it cooler by having the fans run faster is going to give you any speed improvements.
Personally I wouldn't want to tamper with the fan & heat curves...

Big Mac · May 24, 2005, 07:22 AM

I can see where ward is going here. . . I would not mind running having my fans run faster every so often in order to reduce the average internal temperature of my G5. Unfortunately, Apple is very secretive with the fan control software, and apparently people have not been able to figure it out thus far.

phantomac · May 24, 2005, 07:38 AM

Ever thought about looking at the Linux kernel module sources for the kernel module that controls the fans on the G5s? That should help.

ward m · May 24, 2005, 11:07 PM

Thanks for responding everyone!

I can understand your trepidation that it might be possible to do this wrong and damage something via excessive heat, but remember my purpose is to INCREASE the fan speeds for MORE cooling, not less.

A well designed app would take this into consideration and ideally not allow potentially damaging fan speed configurations. The base speeds would be Apple's fan speed curves, and the app wouldn't allow the speeds to go slower than that, only faster. An advanced application like this would probably require Apple's assistance and cooperation, with their intimate knowledge of the OS.

Minus the Marvelous Advanced Fan Speed Control Utility, I'd be happy to just start with increasing all the system fan speeds to full for a few minutes just before shutting down, and avoiding the stewing heat spike as the system powers down and the fans quite completely. I think this might help to increase the life span of the Mac by negating that temporary heat stress. Not really looking for a performance increase. Just a longevity increase. It seems like a more clever and civilized way to shut down the machine.

One interesting thing I noticed is when I boot from the Apple Hardware Test CD (DVD?) that came with my G5, the fans are ALWAYS full on. When I boot normally, off the hard drive the fans throttle way back.

This suggests a couple of possibilities. Either because it's a test application Apple is driving the fans to full because they know the tests will stress the components and heat things up... or...more importantly, because it's on a CD (DVD?) that has limited space, they had to cut a few things out, like fan speed controls. So possibly, in the absence of the OS software fan speed controls, the fans automatically default to full on???

This could possiby be abused, in a positive way, If the OS fan speeds control was just a process running, if you could kill it off would the fans go to full on? This would only be used as part of a shut-down routine, and the killed off process would be reloaded at next bootup. No harm done?

It's probably not that simple, but it would be nice if it was.

Unfortunately, I presently don't possess the depth of understanding of UNIX or the OS that it would take for me to figure out how to do this, so I'll have to defer to the experts and hope someone knowledgeable in the art takes an interest in this.

I have given you some clues. Good luck!

Thanks!

phantomac · May 25, 2005, 01:06 AM

A very simple way to achieve what you want is to open the side panel of the Mac and remove the plastic shielding. Fans turn up to full power when you remove this while running.

Big Mac · May 25, 2005, 03:15 AM

Yes, the fans speed up while the Hardware Test CD is used due to the fact that the controller software is not running, and in the absence of it the system default is for the fans to run at full speed. This also happens when booted into single user mode. Of course, when the full OS is up and functioning normally, so will the fans.

d.fine · May 25, 2005, 07:23 AM

Originally Posted by phantomac

A very simple way to achieve what you want is to open the side panel of the Mac and remove the plastic shielding. Fans turn up to full power when you remove this while running.

That is indeed a way of speeding up the fans before shutdown. But the question is will it shutdown while the air-guidance plastic is not in place? You could just run the G5 with the plastic removed and the Alu side panel in place, but I don't know if this could have any side-effect. I don't even know if the machine would boot without this plastic in place...
Could be worth a try ward m...

ward m · May 26, 2005, 10:07 PM

Hmmm... all very useful information.

I think ideally, however, that the solution should be as simple and elegant as the Macintosh.

Might have to wait for Apple to take an interest. And in fact, they probably already have most of what is needed in place.

Remember that the shut-down sequence and dialog box has a two minute countdown (if it isn't overridden by the user) before powering off the computer. All they have to do is rev the fans to full during this countdown. Would probably only take a couple of lines of code.

They could even add a simple shut-down system preference that toggles this ability on and off, with possibly a user selectable time of from say, one to four or five minutes.

If only...

Anyone have Apples ear???