HP disks on PMAX
Greg Pavlov
pavlov at canisius.UUCP
Thu Oct 25 12:47:33 AEST 1990
In article <28549 at boulder.Colorado.EDU>, grunwald at foobar.colorado.edu (Dirk Grunwald) writes:
>
> has anyone put HP disks, in particular,
> HP97-548S, 5.25 inch SCSI, 793->663mb, 16.5ms seek
> HP97-549P, 5.25 inch SCSI2, 1180->1000mb, 17.5ms seek
> on a DECstation 3100? Will the DECstation handle the SCSI2, as long as
> it's wire compatible with the older SCSI-1 connectors?
I have an answer to this, as well as a Big Question.
We have been using the 663 MB HP disks on DEC 3100's with good success.
BUT (mainly for the HP people out there):
We just purchased a batch of DEC 5000's and have been evaluating both the
HP 663 MB disks and their Seagate/Imprimus/CDC counterparts and have noted
the following:
1. the HP disks cannot be used, at the moment, as boot disks. This has
been verified for us by other parties. The rumor is that HP is about
to release firmware that will solve this problem. Anyone know anything
solid about this ?
2. in many simple tests that we performed, the HP and the Seagate perfor-
med comparably. Except in one area: large bulk transfers. For in-
stance: cp foobar /dev/null :
HP: apx. 650 KB/sec;
Seagate: apx. 1450 KB/sec
Is there any obvious explanation for this ? Our assumption is that
the HPs and the Seagates are comparable capability-wise, but there is
some sort of mismatch/miscommunication between the HP SCSI and the
DEC SCSI interfaces. We see apx. the same results on both the DEC
3100 and the DEC 5000, albeit the Seagate is apx. 25% "slower" on the
3100 (we assume that we are seeing that system's SCSI interface limit).
- to be honest, we would prefer to go with the HP's. But the above are
acting as a major deterrent. We have tried to contact HP directly on
this issue, but haven't got past the secretaries anywhere.
greg pavlov, fstrf, amherst, ny
pavlov at stewart.fstrf.org
716-834-0900
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