I did some similar testing using a Powermac 6400 and a few drives I had on hand, Sandisk Ultra CF card, 1.2 gig Fireball HDD and a 60 gig 7.2k IBM Deskstar. In my test the CF card was the worst of the bunch, but that might be from me using a precreated image and dding it to the drives, not sure.

Here's a link to the graphs. I might redo it later using another system, such as the Powerbook 1400 or see if I can get the Mactel working.

http://imgur.com/a/JxMVa