There won't be a decrease, until you hit the transfer limit of the CF card. On a 2 gig SanDisk Ultra II, the limit is about 13 MB/sec, and around 10 on a standard SanDisk 2 gig card. (Generic benchmark measurement.) On my Tekmagic 2060, I'm getting just under 10 MB/sec with an Ultra II card, which is right around the controller's maximum. (I had to manually set the synchronous flag in HDInstTools, otherwise speed is nearly halved.) I'm pretty sure that the WarpEngine SCSI is also around 10 MB/sec. I also noticed no decrease with an GVP A530 turbo, Impact A500, or Impact A2000. Actually, the CF cards are often much faster than old SCSI drives.
In the case of CS MK3/PPC SCSI, a real HD is probably best. 31 MB/sec on classic miggy is damn fast :-)
