What is your opinion of undervolting as described below? What is undervolting? How is it done?
I just undervolted Pentium M in my nw8240 . It decreases heat emission with no loss in performance. See this tutorial for it: http://www.notebookforums.com/showthread.php?t=70943
I used Centrino Hardware Control rather than RMClock, since I found it to be a little nicer program.
The default voltage at 15x multiplier (2.0 GHz) was set to 1.356 V and at 6X (800 MHz) to 0.988 V. The heat level normally was 85 degrees at 15x and 100% CPU load and 50 degrees at 6x idle.
I was able to undervolt 15x to 1.100 V being stable but I chose to run at 1.116 V just to be safe. The heat level decreased to 70 degrees! So the drop was 15 degrees. The casing (thermal zone 2) is a bit cool er now too - dropped from 85 to 75 or so. It still heats and is of course noticeable, but all this for free is a good deal.
I undervolted 6X to 0.700 V and it worked well, but I didn't notice any difference in idle temperature. Well, maybe 1 or 2 degrees.
Well, is undervolting worth the trouble? Maybe. The computer heats a bit less, but actually it doesn't heat so much normally either - at least mine doesn't. But since undervolting is a free upgrade, you can just do it if you have time. Of course, if you don't mind testing stability, you may just pick some numbers (like mine) and let it go and hope that it's stable for your CPU as well. But note that my stable voltage was a few steps higher than that of the original undervolting thread starter, even though we have the same CPUs, so the stability of an individual CPU cannot be guaranteed without testing.
EDIT: 1.116 V wasn't working perfectly, so I'm running at 1.132 V. So far so good.
EDIT 2: Undervolting increases battery life, I could run the DVD test again at some point and see how the laptops performs now.