23 August 2011

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
3,000
300
2 with eSATA HBA (1 with passive adapter)
No
1 (15 with port multiplier)
5 V/12 V
6,000
600
1
No
3,000
300
1,500
150
1 per line
PATA 133
1,064
133.5
0.46 (18 in)
No
2
6,000
600
10
No
1 (>65k with expanders)
3,000
300
1,500
150
IEEE 1394 3200
3,144
393
100 (more with special cables)
15 W, 12–25 V
63 (with hub)
786
98.25
100
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
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

No comments:

Post a Comment