Using the late Glen Bredon?s Prosel 16 utility Volume Repair, Statistics on Disk Access, I came up with these numbers. The results are the average of 3 runs.
Using the Apple Hi-Speed SCSI card with a Quality Computer Q Drive 40MB:
Linear Read = 1.75 ms
Random Read = 24.84 ms
OS Overhead = 8.79
Using the RamFast SCSI Rev. D card, ROM 3.00j, with the Q Drive:
Linear Read = 1.57ms
Random Read = 14.4ms
OS Overhead =1.01ms
Using the CFFA card with 2GB Sandisk card
Linear Read = 3.18
Random Read = 3.83
OS Overhead =0.34