I’ve recently been having some kernel panics and rebooting/crashing on my MacPro 1,1 running 10.6.8 and Lion and some suggested it could be my CPUs overheating. There was a suggestion to install SMCfancontrol and run all fans and a higher speed and keep an eye on temperatures whilst stressing the CPUs to 100% for a prolonged period. So below is a little bit on info on how to crank your CPU up to 100% usage and monitor core CPU temperatures.
Getting you CPU to 100%
There are several ways to max out your CPU, some suggest ripping movies using Handbrake or re-encoding your music library but personally I don’t want all the faff with that plus these methods are IO intensive for your hard drive which isn’t good. All I do is open up Terminal (Applications/Utilities/Terminal) and then once it’s opened type
yes > /dev/null
and hit return.