Hi,

At 01:41 PM 6/5/97 -0700, Lee Gunter wrote:
>EMC Symmetrix arrays use FW-SCSI connections to the HP3000, and are
>configured using either the DARRAY device ID, if you're running MPE/iX
>5.0 PP6 (minimum) or the SYMMETRIX ID if you're running 5.5 PP1 or
>better.  Performance gains for us were significant - particularly for
>batch processes.  Disk service times average 10-20 ms compared to 25-60
>ms for our Cascade disk arrays (C225xHA).  We still run a mixed DASD
>environment, but we will eventually migrate most, if not all, of our
>volume sets to Symmetrix disk.
>

One key thing to keep in mind about Lee's performance improvements is
that he migrated from the Cascade disk arrays (as he said) which have
nowhere near the performance of more recent disk drives.  Most newer
disk drives have disk service times in the mid-teens to mid-twenties
(in milliseconds) whereas with the EMC's you will probably average
in the 8-12 millisecond range.  Still a great improvement, but not
as dramatic as what Lee experienced.

Bill Lancaster