Comment 101 for bug 22336

Acer Aspire 1640Z series. 1 year old. Runs maybe 4 hours a day at different intervals, normal power down in between uses.

Up until 2 weeks ago, this notebook ran Windows XP exclusively. And it NEVER had a problem with excessive heating, certainly not tripping any hardware BIOS emergency shutdown.

2 weeks ago, I installed Ubuntu Edgy. It is up to date with the "recommended updates" (that little orange and white icon on the task panel). This machine has shut itself down at least 4 times and it is definitely heat-related, judging firstly from empirical evidence. In fact, in one really bad shutdown, the computer refused to power on for several minutes, as it was apparently really hot. I've since installed the monitor applets (battery, CPU/hardware temp, and CPU throttling). So far I've seen it topped out at like 50-62 C, which is fairly warm, but not dangerously so. I've seen the CPU throttle up and down from 600 MHz to 1.7 GHz (max). Temperature spikes during CPU throttle up and then drops on throttle down. At idle, it's in the 35-45 C range.

I have to admit, I have yet to do any of the customizations that I've seen in this thread, such as the 'powernowd' and 'ondemand', nor have I mucked with the trip points for passive mode cooling -> active mode cooling. I am going to try those two. I am also going to look in the log files for more clues. The only thing I have done is set the suspend timeouts to lower values, just to keep it from idling hot when it doesn't need to be...and I also updated my BIOS just in case.

I'm following a lot of the discussion here without much trouble except for this DSDT. Can someone explain to me what DSDT is and what role it plays in all this?