which Linux distro runs iMac the coolest temperature

[marc_Linux]

recently tried Linux Mint on my old 2008 iMac 20"
it installed fine, ran well enough, hardware worked etc.

Problem is - the iMac runs way hotter that it does on any Mac OS and,
even Win7, when slightly tweaked on the iMac, runs almost as cool.

Years ago i had overheating problems with various Linux on different generic PC
laptop hardware, and i ended up recompiling the kernel with wait stated and throttling
and speed step enabled, i don't want to have to do that again just to run Linux on this old iMac.

Some distro's used to spin a separate distro specifically for Mac hardware, but looks like
that has gone out of fashion too.

Can anyone recommend any Linux or BSD that will actually run the hardware as cool as Mac os X and Windows can ?

 

[awediohead]

recently tried Linux Mint on my old 2008 iMac 20"
it installed fine, ran well enough, hardware worked etc.

Problem is - the iMac runs way hotter that it does on any Mac OS and,
even Win7, when slightly tweaked on the iMac, runs almost as cool.

Years ago i had overheating problems with various Linux on different generic PC
laptop hardware, and i ended up recompiling the kernel with wait stated and throttling
and speed step enabled, i don't want to have to do that again just to run Linux on this old iMac.

Some distro's used to spin a separate distro specifically for Mac hardware, but looks like
that has gone out of fashion too.

Can anyone recommend any Linux or BSD that will actually run the hardware as cool as Mac os X and Windows can ?

I know this is an old thread but hope the following will be useful as I've just been resurrecting an old 2008 MacBook and 2007 MacMini with Linux - after all many people started building hackintoshes because apple stopped supporting perfectly capable hardware. For eg the MacBook above has a 64bit EFI and 64bit Core2Duo CPU and yet was artificially limited to Lion by Apple wanting to force obsolescence. Same applies to my Mac Pro 1,1 but that's fairly easy to install 10.11 on with a few tweaks - the rest are best kept running with Linux.
To answer the question in the OP: This isn't so much about a specific distro as doing some stuff post-installation on ANY distro
Anyone using Linux on an older Mac should search the web for how to install hardware monitoring so the temperature sensors built in to the mac can interact with software and the OS.
This is likely possible through some of the bigger "software boutique" type stores/repos on a modern linux distro, but otherwise you'll need to get into the terminal

 $   sudo apt-get install lm-sensors hddtemp psensor

start detection:

 sudo sensors-detect

verify:

sensors

Then you can open psensor as a desktop app and see a graphical display
Also have a look at this - which I just stumbled across - and which I will be installing asap.
https://github.com/dgraziotin/mbpfan