Data Storage - Number of drives per RAID controller channel (Ultra320)?

Author

Number of drives per RAID controller channel (Ultra320)?

Benno

2005-05-01, 5:49 pm

Is there anything to say about the maximum number of drives you should
connect to a Ultra320 channel on a RAID controller (for a single RAID5 set)?
Modern Ultra320 10.000RPM drives have a throughput between 59 and
118MB/s (according to Seagate datasheets). Does this mean you can only
have 3 to 5 drives on a single channel before you saturate the channel?
If this is the case, is it useful to invest in a dual channel RAID
controller (HP SmartArray 6402) and evenly divide the drives between the
two channels?

Bill Todd

2005-05-01, 5:50 pm

Benno wrote:
> Is there anything to say about the maximum number of drives you should
> connect to a Ultra320 channel on a RAID controller (for a single RAID5
> set)?

No - because, as usual, it depends heavily on how you're using the drives.

> Modern Ultra320 10.000RPM drives have a throughput between 59 and
> 118MB/s (according to Seagate datasheets).

Or, if you're performing random single-sector accesses, a throughput of
well under 1MB/sec.

- bill