What temps on iMac

[pt0016]

Hi there,

Does anyone know approx when the each of the 3 fans are supposed kick in? On an iMac Late 2009, 21.5" 4670HD

Was in BootCamp, playing GTA IV, and noticed the top of iMac was very hot, and I booted into OS X to check temps, CPU was 45degrees and gfx card was 65degrees (celsius), but you still could not hear the fans, with the fans being around 1000rpm. - Not changed from idle fans speeds.

Is this normal behavior? Thanks, any help appreciated.

[TMRaven]

The iMacs have aluminum cases, and aluminum conducts heat very well, and heat rises, so of course the top of the iMacs will get hot. Touch the bottom to find that the case is rather cool.

For me, the fans kick in when the cpu nears 70c, the gpu nears 80c and the hdd nears 60c.

[3rd Doctor]

It's normal.

[Mr. McMac]

The top of my 09' 24" iMac gets very hot to the touch as well. It's normal

[aki]

As you may know, Apple's automagical fan control system works well enough in OSX but (apparently) doesn't work so well when you are under bootcamp Windows. Hence, people experience higher temperatures under Windows than "normal". If you do heavy gaming under Windows for long periods on a regular basis, you may want to consider a manual fan-control solution.

I have a long spiel about iMacs and heat that I have taken to copypasting in threads like this but I don't want to spam you with things you already know. :p If interested lemme know and I'll dump it here.

Two quick points tho. First, correct, touching the iMac tells you nothing (useful) about internal temperatures. Second, the CPU and GPU are pretty hardy, your most heat-vulnerable internal component is your HD.

[AlexisV]

Hours in Crysis under Windows XP makes the machine no hotter than hours playing Quake Live on OS X for me.

[Dichotomic]

You can install SMCfan Controller on any intel based Mac's to control the fans manually. Google it to find the app. I always crank them to max before I go into a windows to game. As long as you reboot, and not shut down, the fan settings stay the same. I don't find windows does a very good job with automatically controlling them.