Is there any program out there allowing you to test the RPM of your HD under Mac OS X? I have a few 3rd party HD and have no idea what speed they are.

Also my other Mac is a mini 1.42ghz. I believe they had the 4200rpm? I know they where upgraded to 5400rpm. Is there any chance my mini has one of those or was it only for the 1.5ghz model?

Thanks for your help.

Usually you can find out the specs for your hard drive (including rpm) from the System Profiler:

Spotlight System Profiler, then see if you can spot something that looks a little like
Model: SAMSUNG HM250JI
under "ATA" in the left hand pane.

Google the model number, and viola - you should be able to find lots of info on your hard drive, including RPM speed.

Note that this also works for any externally-attached drives - you'll just have to look in a different spot in System Profiler (under Firewire or USB) but the info should still be there

Alternatively, you can see the same info in Disk Utility, where if you click on the Hard Drive (not the partitions) you will see:
Disk Description : SAMSUNG HM250JI Media
down the bottom. Same procedure applies for the RPM speed - just Google the model number, and you're all good!

You don't even have to use a computer to check the drive, if the hard drive is a bare chamber -- simply look on the drive's label, they will often quote the RPM, and if they don't, google for the drive's model number to track down its specs.

Cheers boys.