Tracy R Reed wrote:
Gregory K. Ruiz-Ade wrote:
In terms of Fiber Channel drives, are they even available in 2Gbps or
4Gbps models, or do the higher-speed FC fabrics rely on device
aggregation to push the higher throughputs even with 1Gbps interfaces
on the drives themselves?
No drive will push 2 or 4Gb/s. The bus is that fast because you put many
drives on that same bus and stream from them all at once. I've had
50-100 drives all on one FC bus before. Some folks probably do many more
than that.
The new ones are within shooting distance of 2Gb/s.
A Hitachi Ultrastar 15K147 has a media transfer rate of 1129Mbits/sec
which is about 1.102Gbits/sec.
The claim is a sustained data rate of 93.3MB/sec which is about
746Mbits/sec (x8). Normally, though, serial signalling requires
overhead and is normally about x10 instead of x8. That would put
933Mbits/sec on the wire.
That's a lot of data from just a single drive.
Those transfer numbers are one of the reasons why faster drives really
haven't taken off in major numbers. A single 15K drive moves more data
than wide/fast PCI. 15K drives *require* PCI-E or PCI-X.
-a
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