How does USB Port compare to other connections used with PCs and workstations?

Here's a quick list of the maximum transfer rates for various connections in megabits (Mb) and mega-bytes (MB) per second:

Serial port: 115kbits/s (.115Mbits/s)
Standard parallel port: 115kBYTES/s (.115MBYTES/s)
USB: 12Mbits/s (1.5MBYTES/s)
ECP/EPP parallel port: 3MBYTES/s
IDE: 3.3-16.7MBYTES/s
SCSI-1: 5MBYTES/s
SCSI-2 (Fast SCSI, Fast Narrow SCSI): 10MBYTES/s
Fast Wide SCSI (Wide SCSI): 20MBYTES/s
Ultra SCSI (SCSI-3, Fast-20, Ultra Narrow): 20MBYTES/s
UltraIDE: 33MBYTES/s
Wide Ultra SCSI (Fast Wide 20): 40MBYTES/s
Ultra2 SCSI: 40MBYTES/s
IEEE-1394: 100-400Mbits/s (12.5--50MBYTES/s)
Wide Ultra2 SCSI: 80MBYTES/s
Ultra3 SCSI: 80MBYTES/s
Wide Ultra3 SCSI: 160MBYTES/s
FC-AL Fibre Channel: 100-400MBYTES/s
The fastest connection commonly found on PCs is UltraIDE, which is used for hard drives and CD-ROMs.

Last updated: 03-07-2006
Author: Mihai