So what advantages are there to going SCSI? Well for one -- upgradability. With most controllers offering support for up to 15 devices, it may be a while before you need to think about anything new. Also, SCSI is faster. Not only does the interface support higher bandwidths than even UltraDMA/66, but SCSI cards have dedicated processors, taking away some interaction with the CPU. Beyond this, SCSI drives are bigger. With mainstream drives already at 36Gigabytes, and some monsters up around 50Gigs, IDE has some catching up to do.

Capacity (formatted) Disks/Heads Disk media diameter Bytes/sector Cylinders Sectors/track Recording density Track density Buffer size Interface Seek time Data transfer rate Start time Stop time Rotational speed (RPM) Average latency

18.2 Gigabytes 5/10 3.0 inches 512 9,866 278 to 420 (14 zones) 275,000 Bytes Per Inch 13,500 Tracks Per Inch Ultra2 SCSI 2048 Kilobytes Ultra2 SCSI (Low Voltage Differential) Track to Track Read: 0.7 milliseconds (ms) (typical) / Write: 0.9 ms (typ) Average Read: 5.2 ms (typ) / Write: 5.8 ms (typ) Full Track Read: 11.0 ms (typ) / Write: 12.0 ms (typ) To/from media 30.3 to 45.0 MB/second 29.5 to 45.0 MB/second To/from host Ultra2 SCSI: up to 80 MB/second 30 s 30 s 10,025 2.99 ms