[Sunhelp] Performance increase w/scsi ?

[Fuerst, Robert C. (Chris)]

I didn't think anyone used 5400 rpm drives anymore.  Here's one from
Seagate.....

The newer Barracuda 18LP or Cheetah 18LP would be the most appropriate for
the Sun systems you have, since both drives will work on standard Wide SCSI
interfaces.
You probably cannot install the newer Ultra160 SCSI compatibility in your
system unless you have at least one PCI available in each system, and that
host adapter card you choose features driver support for your version(s) of
Solaris.  The Barracuda and Cheetah models currently shipping only support
Ultra2 Wide SCSI, which has a maximum bandwidth of 80 Meg/sec.  Therefore,
they could not every reach data rates about 80 Meg/sec.
The newer and unreleased Barracuda 18XL and Cheetah 18XL/36LP will support
Ultra160 out of the box, but these drives will not be available until
sometime in the first quarter of next year.
The "LW" suffix of our models now indicates the 80 Meg/sec data rate, but
the LW suffix will also be used on the newer drives to indicate 160 Meg/sec.
To differentiate, you would need the exact model number of the drive and
then check the actual specifications to find out if the model supports 80,
160, or both.  The older "W" interface was 40 Meg/sec burst rate, but those
drives are no longer made in favor of the "LW" drives being backward
compatible to that architecture and burst speed.
If you use current drives on an older Fast Wide (20 Meg/sec) interface, you
will still reap all the benefits of the lower seek times, the RPM, and other
attributes of the 10,000 RPM Cheetah rives, but the data rate of the drive
will suffer since the interface will limit the drive to a maximum rate of 20
Meg/sec.  You would have to upgrade the host adapter or SCSI controller
subsystem in your machines in order to fully realize the speed potential of
newer and faster drives.  In any case, any current drive will most certainly
outperform the older ST19171W drive you currently have.
Brian W.
Seagate Technical Support


-----Original Message-----
From:	Bill Bradford [SMTP:mrbill at mrbill.net]
Sent:	Friday, April 21, 2000 1:13 AM
To:	sunhelp at sunhelp.org
Subject:	[Sunhelp] Performance increase w/scsi ?

I'm thinking of switching my Ultra 10 (which currently has the old 4500rpm
4.5gig IDE HD and 24x IDE CD-ROM drive in it) so that its SCSI-based (12x
Plextor CD-ROM drive, Seagate Barracuda 5400rpm 4gig HD).  Anybody know what
kind of speedup improvements I'll see?

Even tho this U10 has 300mhz/512k, this HD *definitely* slows it down - it 
seems slower than my U5/270mhz that had a 8.4gig Seagate HD in it (5400rpm
I beleive).  Can definitely tell the difference.

Bill (still looking for a 24bit card..)

-- 
+--------------------+-------------------+
|   Bill Bradford    |   Austin, Texas   |
+--------------------+-------------------+
| mrbill at sunhelp.org | mrbill at mrbill.net |
+--------------------+-------------------+
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