"After reading some of Jim Hamm's comments on iStat I located the widget and added it to my dashboard." David Passell continues, "Yesterday I ran it after noticing the fan on my Mini seemed to be working rather hard. I found that something, I still don't know what, was continuously consuming 95% of processor time. Both processors were being involved. I decided I had better give the machine a rest and shut it down for the night. This morning when I started the Mini I looked at iStat and found more reasonable numbers." Above is the first screen shot. (Double click on it to enlarge the view.)

"As I write this email here is a screen shot of current usage.
I noticed earlier that when the Time Machine backup was running, usage went up to 47%. I just thought it interesting to note and it may have saved my computer to shut it down when it was whirring away.

"Now I keep the CPU Monitor on the screen out of the way so I can spot anything like happened yesterday. The Mini is now nearly silent, as usual." David adds, "Any ideas, anyone?"

Now, Art Gorski has some suggestions: "I've used iStat for years now, and it's occasionally useful as a Dashboard Widget, but can be unnecessarily distracting. Usually, the first sign of a runaway process will be the cooling fans spooling up. iStat won't tell you anything useful, it just confirms what's going on.

"Restarting the computer is unnecessary. Just launch Activity Monitor (in your /Applications/Utilities folder), select all processes from the pull-down menu, and then click on the column header to sort by CPU usage. This will tell you what application is the culprit. If it's not a critical application, use Activity Monitor to quit or force quit the offending process."