Sorry to revive this old thread, but I just built a little Linux server here to have access to my archives from anywhere and stream  media. Using  Amahi with Ubuntu 12.04 : works really well, very stable, with a VPN, etc. A couple bumps on the road, but it was mostly my fault (didn't follow the steps carefully enough when I first entered my addresses from another laptop, etc.), but since I chose to do that on my old laptop (which comes with a free UPS...  ;))... I was bound to have heat problems; that is because I changed he CPU a few years ago for something a but too powerful for the ventilation system it seems (?). On windows, I had to undervolt it, as mentioned above.

I almost thought I would be out of luck with Linux when the CPU hit 98 degrees 2 days ago... but , but... NO! there was a solution out there and I was able to once again successfully undervolt my T7500 using Linux PHC and following the steps on the 2 pages bellow. I used the voltages I previously used for Windows' RMClock. I actually dared to go even lower, successfully. If you're using Ubuntu and you follow the guide precisely, you shouldn't have any problems doing the same, unless your CPU isn't supported.

CPU Undervolting with Ubuntu 12.04

and

How to set the CPU voltage


A couple advices, once you're done with the steps :

1- Make sure you're loading the right patched kernel (the PHC one). In the Ubuntu boot/Grub menu, you'll find it in "Previous Linux versions" I think. No PHC kernel = no undervolting.

Once you know the kernel seems to work properly, edit your  /etc/default/grub file to load it as default. Using a GUI is probably the most intuitive and safe way to do it. Something like Grub Customizer. Install that (follow the steps in the previous link) and move the PHC kernel so that it becomes the 1st kernel entry)

2- make sure the PHC module is loaded automatically (phc-intel).

Open a terminal window and write/paste:
I nothing happens you need to add this to the etc/modules file (on its own line) : phc-intel

(For those who don't know how to do this, you'll need to edit the file as a super user; try "sudo nautilus", enter your password and browse to etc/modules
OR if you feel comfortable in nano :
edit your file, then ctrl-x, type "y", enter, ctrl-x again.)

3- to add phctray.sh as a startup app, it's easiest to just hit the "windows" key, type "startup", run the startup app, and then add /**your_path**/phctray.sh as a new item (fill the appropriate textbox)

4- Make sure that phctray (or  phctool) is running. Use "System Monitor" (same as Task  Manager) to check that out. if none of them are, your changed voltages won't be loaded. Something failed in the steps before.

5- You could double check that your voltages/multipliers are correctly saved in  home/**YourUserName**/.phcstore.phc
(you can actually even change the settings there, directly, if you know what you're doing)
If you can't see the file, you might be hiding config files. Hit ctrl+h in Nautilus. Or change that in the preferences somewhere.
 
... anyway


You might run into other problems, but... I didn't. I actually only had to add the module to the modules file

A few hours of work (2-3) and it's so worth it. Amazing how cool this machine is running when under 100% load !

Thanks Wraith.
Strange. I thought Windows 8 (maybe vista and 7 too, don't remember as I was on XP right before 8 ) treated priority changes at the "instance" level, so to speak. In any case, I can confirm that priority changes certainly don't stick here.

You're right, it seems very slow loading the first time.  But bring it up again and it's faster the second and subsequent times.

-x16wda (July 14, 2013, 02:31 PM)

You might be right about that. I'll have to experiment some more. What might happen is that I very often put my laptop in standby mode, which probably flushes the caches -- sorry if the term isn't perfectly accurate.
Still...