The only easy way I can think of is by use of one of the S.M.A.R.T. disk monitors. This will give you the model numbers of the disks, and you can then search for them on the web. I just checked mine and did a search on the three disks, came up with complete specs on each. I have the complete mix, an 18gig 10kRPM Ultra SCSI boot disk, and a 7200 RPM 120gig archive and a 5400 RPM 60gig archive.