MBP fans not spinning up under stress?

I noticed a while ago that when I fired up a game on my MBP that the fans would spool up to their maximum. Lately, I've noticed that they've not been doing that. I had been using SMCFanControl, but I uninstalled it completely, turned my system off, and restarted. I've run a CPU stress testing benchmark, and the fans aren't spooling. The fans work because SMCFanControl did. Is something amiss?

 

Must have been my imagination because I've been running two instances of Prime95 in order to max out both processor cores, and sure enough, those fans spin right up when the temps get high enough.

I also found a different fan control app for OS X, called Fan Control (interestingly enough). It runs in the system preferences panel and allows fan speed adjustments based on temperature. It's not quite as flexible as SMCFanControl, but it does what I need.

 

Fan control did it. It did the same thing to my system and fan behavior has never been the same as it was factory. Fan Control, not SMCFanControl is the problem. The program actually screws with your SMC and modifies parameters which is impossible to reverse. Let me know if you find an answer.

 

I've read about this on Fan Control's forum, and it seems that the developer is oddly silent about it....

However, I was saying that I actually like the way Fan Control works. No harm, no foul there, at least on my system. If you need to completely remove it, apparently the only way is to do a firmware restore. Fortunately, Apple makes restoration CD images available for download here. That link is for Intel-based Macs. If you have a PPC/Gx, check the Apple support site for an image that will work on your system.

Hope this helps.

 

Note: This CD cannot be used to return an Intel-based Macintosh computer's firmware to a previous version if a successful update has already been performed.

The CD won't help. The problem with Fan Control is the effect it has on battery life.

 

My fans work fine in XP...The fans also work in OS X but take a hell of alot longer to speed up than when I first got the computer before installing Fan Control.

 

Have you tried resetting the SMC?

http://docs.info.apple.com/article.html?artnum=303319

Excerpt:

That should return the SMC to factory settings. I don't think there are any parts of the system that can be permanently damaged by software...

 

Yep, resetted that like 10 times, resetted the PRAM and even did a whole reformat.

Maybe the system is running normally, but I definately have noticed that the fans do not speed up to 6k in 10 seconds like they used to when I am running something intensive.

How long does it take your fans to spin up when you run an intensive program? Or does it spin up after a while of being hot?

 

I didn't really pay attention, but I started up Windows XP from a cold boot (left system off overnight) and fired up some Half-Life 2. After a minute maybe the fans spun up. It didn't seem to take unusually long.

 

Yeah no problems in XP for me here also. How about in OS X? when you run your cpu at 100%?

 

Fan Control works as advertised for me. The fan stays at my pre-set speed of 2700 RPM when the temp is below 55 degrees. Above that, it scales appropriately. I have the upper bound set at 70 degrees and the fans seem to go full-tilt boogie when temps reach that mark. No problems at all on this end.

 

I uninstalled Fan Control a long time ago. I hope you know that if Apple discovers it they WILL void your warranty if you bring it in for any reason.