Does a SCSI have the fastest throughput?

Answer 1

It used to, but no longer.

These days, for individual harddrives, SATAII and SATAIII (SATA3) are significantly better in performance.

However in terms of total throughput performance, SCSI can outperform even SATAII.

Here's a breakdown of common interfaces and their bandwidth:

ATA/100 (IDE): 100 MB/s

Ultra ATA/133 (IDE): 133 MB/s

SATA: 150 MB/s

SATAII: 300 MB/s

SATAIII: 600 MB/s

Ultra3 SCSI: 160 MB/s

Ultra-320 SCSI: 320 MB/s

Ultra-640 SCSI: 640 MB/s

SAS (Serially Attached SCSI): 300 MB/s

USB1.0: 1.5 MB/s

USB2.0: 60 MB/s

Firewire: 50 MB/s

Firewire800: 400 MB/s

100mbit Ethernet: 12.5 MB/s

Gigabit ethernet: 125 MB/s

Average Cable internet: 1 MB/s

It should be noted, however, that the world's fastest harddrives do not max out most of these interfaces.

An Atlas 3k (15,000 RPM) drive uses SAS, Ultra-320 and Ultra-640 interfaces, but tops out at 145 MB/s average with 202 MB/s peak.

As such, whether to use SCSI or SATA is of no importance to standard users. Only servers and mainframes typically need to worry.

That, combined with the MUCH higher cost of SCSI drives and SCSI interface cards (and cables) has left SCSI unpopular and largely obsolete.