Computer runs very hot when idle

[Pedro Côrte-Real]

I have a white macbook. It's the first edition with a core duo 2.0Ghz (32bit) processor. The CPU seems to run at a normal (if a bit hot) 50C when using it normally at 1GHz (speed scaling) with a very low fan speed. What's strange is that if I'm not using the computer it climbs all the way to 77C and yet the fan is running at full speed. As soon as I move the mouse or write something with the keyboard it goes down fast to 46C and then back up to the normal 50C. I'm guessing the temperature is not being correctly reported for some reason. This could be related to Bug #52852.

A strange thing about this is that the computer wasn't completely idle during these tests. I had a bittorrent download running in the background. I guess it could be a problem of the CPU entering those power saving C states that doesn't happen when there are keyboard/mouse interrupts.

I measured the temperature using coretemp.c but I was only able to measure it for the first core because ubuntu's msr module doesn't create /dev/cpu/1/msr for this dual core machine. This shouldn't make a difference since the cores are in the same die and should be at the same temperature.

[Pedro Côrte-Real (pedrocr)]

I knew this other but and i don't think this is a duplicate. The problem only happens when idle and the computer is running with the fan at full speed so it's probably not actually hot but just misreporting it. It may have the same underlying cause though.

[martinbures (needemesleepe)]

I have the same machine. It runs hot and gets about half of the battery life as OS X 10.4.8. It does not seem like the frequency scaling mechanisms are working properly.

If you let me know what information to provide to help diagnose this problem, I will provide it.

[martinbures (needemesleepe)]

By the way, I am running a fully-updated Edgy Eft.

[Rune (rthil)]

I have the same problem with my first edition macbook and feisty. Did you find a fix for the problem?

[Launchpad Janitor (janitor)]

The 18 month support period for Edgy Eft 6.10 has reached its end of life. As a result, we are closing the linux-source-2.6.17 Edgy Eft kernel task. However, development has already began for the upcoming Intrepid Ibex 8.10 release. It would be helpful if you could test the upcoming release and verify if this is still an issue - http://www.ubuntu.com/testing . If the issue still exists, please update this report by changing the Status of the "linux" task from "Incomplete" to "New". We appreciate your patience and understanding as we make this transition. Thanks!

[oss_test_launchpad (oss-test-launchpad)]

I am marking this as a duplicate since there has been no acitivity here for quite some time and there is a newer discussion available. Hope you dont mind.