Transfer Bus Comparison

With newer portable hard drives starting to commonly show up on price lists and shop windows I thought it was time to update myself on the pros, the cons , and the performance of the various bus types.  The table give a very good indication of what the capabilities are.  This table is from Wikipedia and the links refer back to the various Wikis

It is very interesting to note how the newer bus types start matching or exceeding the performance of the former   server class buses such as SCSI, SAS and Fibre Channel.

Name	Raw bandwidth (Mbit/s)	Transfer speed (MB/s)	Max. cable length (m)	Power provided	Devices per channel
eSATA	3,000	300	2 with eSATA HBA (1 with passive adapter)	No	1 (15 with port multiplier)
eSATAp				5 V/12 V
SATA revision 3.0	6,000	600	1	No
SATA revision 2.0	3,000	300
SATA revision 1.0	1,500	150			1 per line
PATA 133	1,064	133.5	0.46 (18 in)	No	2
SAS 600	6,000	600	10	No	1 (>65k with expanders)
SAS 300	3,000	300
SAS 150	1,500	150
IEEE 1394 3200	3,144	393	100 (more with special cables)	15 W, 12–25 V	63 (with hub)
IEEE 1394 800	786	98.25	100
IEEE 1394 400	393	49.13	4.5
USB 3.0*	5,000	400	3	4.5 W, 5 V	127 (with hub)
USB 2.0	480	60	5	2.5 W, 5 V
USB 1.0	12	1.5	3	Yes
SCSI Ultra-640	5,120	640	12	No	15 (plus the HBA)
SCSI Ultra-320	2,560	320
Fibre Channel over optic fibre	10,520	1,000	2–50,000	No	126 (16,777,216 with switches)
Fibre Channel over copper cable	4,000	400	12
InfiniBand Quad Rate	10,000	1,000	5 (copper) <10,000 (fiber)	No	1 with point to point Many with switched fabric
Thunderbolt	10,000	1,250	100	10 W	7

One thing to keep in mind though, is that although the various hard drives / flash drives etc are attached to a very fast bus, it does not mean that you will get this performance.  You will most often be limited to the transfer speeds of the devices on either side of the bus.

For the full source article http://en.wikipedia.org/wiki/Serial_ATA