SCSI or EIDE?

With higher data densities, quicker head movement, and faster spin rates, hard drives deliver data much faster than they used to, some with sustained rates higher than 8 MB/second. Both the IDE (as EIDE) and SCSI device interfaces have kept pace; either can shoot data to the host PC faster than a single drive can deliver it. So why are high-end Windows NT systems faster with SCSI drives? For single-drive systems that don't fully use SCSI multitasking, an EIDE drive may have a slight performance advantage over a SCSI drive because it has a simpler, more direct interface with litt le command overhead. The answer is that drive manufacturers put SCSI connectors on their fastest and most expensive drive mechanisms. Currently EIDE (or ATA) drives top off at 5400 rpm, while many high-end SCSI drives do 7200 rpm. Spin rate affects both sustained data rate and access time.