Slow transfer speeds with U320 drives and HP Smart Array 641

Nelis Lamprecht nelis at
Tue Mar 23 23:57:09 PST 2004


With the ciss driver on my HP ProLiant ML350 I've noticed the transfer
speed on my RAID controller is only.

da0 at ciss0 bus 0 target 0 lun 0
da0: <COMPAQ RAID 1  VOLUME OK> Fixed Direct Access SCSI-0 device
da0: 135.168MB/s transfers
da0: 69459MB (142253280 512 byte sectors: 255H 32S/T 17433C)

Both my drives on the RAID controller are U320 72GB pluggable SCSI's.
The RAID card also has the optional 64MB battery backed write back cache
enabler installed.
I also have a AIC 50/100 Tape Drive in the machine which is connected to the
onboard SCSI interface.

sa0 at ahc1 bus 0 target 6 lun 0
sa0: <COMPAQ SDX-500C 1.35> Removable Sequential Access SCSI-2 device
sa0: 40.000MB/s transfers (20.000MHz, offset 7, 16bit)

My question is why the slow transfer speed of the RAID controller ? Does this
have anything to do with the slower SCSI Tape Drive or is this a limitation of
the ciss driver ? Or perhaps I have misconfigured something ?

Any advice would be appreciated. Thanks for your reply.

Kind Regards,

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