fr@icdi10.UUCP (Fred Rump from home) (02/10/91)
The Micropolis 1684 SCSI drives promise something like 3.9 MS 'effective'
access time with something like a 4.0 MB/sec transfer rate.
Sounds great.
Anybody use these yet? And how fast are they really?
What controllers have you used?
I'm particularly interested for functionality under SCO UNIX or Xenix.
Interested customers would like to know.
Fred
--
Fred Rump Secrets of success: When you start a job, FINISH IT ...
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609-386-6846 "Freude... Alle Menschen werden Brueder..." - The Odefmiller@dobie.UUCP (Fred Miller) (02/12/91)
fr@icdi10.UUCP (Fred Rump from home) writes: >The Micropolis 1684 SCSI drives promise something like 3.9 MS 'effective' >access time with something like a 4.0 MB/sec transfer rate. >Sounds great. >Anybody use these yet? And how fast are they really? >What controllers have you used? >I'm particularly interested for functionality under SCO UNIX or Xenix. I think the general concensus is that the "best" host adapter (most SCSI controllers are on the hard drive) is the Adaptec 1542, current version is "B". I haven't used the Micropolis 1684 so maybe someone else can help you with that. Fred -- F&J Enterprises | bluemoon!dobie!fmiller International Network Marketing | The Common Sense BBS P.O. Box 102 | When you get tired of high taxes, Lansing, NY 14882-0102 | vote the bums OUT!
jim@tiamat.fsc.com ( IT Manager) (02/12/91)
In article <1351@icdi10.UUCP>, fr@icdi10.UUCP (Fred Rump from home) writes: > The Micropolis 1684 SCSI drives promise something like 3.9 MS 'effective' > access time with something like a 4.0 MB/sec transfer rate. > > Sounds great. > > Anybody use these yet? And how fast are they really? > What controllers have you used? > I'm particularly interested for functionality under SCO UNIX or Xenix. > We installed a Micropolis 1684 (5.25", 1/2 height, 323MB available to Xenix) on a Xenix system a few weeks ago. The host adapter is an Adaptec 1542B (it has worked with the 1542A as well). I have been satisfied with its performance, but we ran into a few incompatibilities. For instance, this drive works fine right now when teamed with a Miniscribe 8380S drive. But, when teemed with either a Syquest SQ555 or Miniscribe 3180S on the same SCSI bus, we would get system lockups. Also, when the 1684 and 3180S were on the same bus, it seemed like there were times when the 1684 would power off, and then back on again. This isn't new to me, as we had other compatibility problems with SCSI drives in the past. It's always been pretty easy to just use two host adapters and divide the drives into two groups that work well together. As far as performance goes, here's some numbers: from "time dd if=/dev/XXXX of=/dev/null bs=100k count=10" for the Miniscribe 3180S 10+0 records in 10+0 records out real 17.7 user 0.0 sys 0.4 for the Miniscribe 8380S 10+0 records in 10+0 records out real 17.9 user 0.0 sys 0.5 for the Micropolis 1684 10+0 records in 10+0 records out real 3.9 user 0.0 sys 0.6 On the surface (and definitely under this installation) the Micropolis is much faster. These drives are are installed in their "default" state, so there has been no performance tuning. These drives will be involved in an upgrade soon, and before we install the OS, I'll use Roy Neese's SCSICNTL program to try to do some fine tuning on the drives. BTW, using the built-in diagnostics on the 386 these drives are installed on shows that the Micropolis and Miniscribe 8380S (which are mapped to drive C: and drive D: by the Adpatec BIOS) have similar performance (I don't remember the exact numbers, but they were in the 900K/sec neighborhood), with the Micropolis having a much faster seek time (in the 4ms range, compared to about 7.5 for the Miniscribe). This might explain the difference in performance as seen under Xenix. I really like the price, performance, and reliability of SCSI drives, but the incompatibilities I keep seeing make me wonder some time just how "standard" SCSI really is. ------------- James B. O'Connor jim@tiamat.fsc.com Ahlstrom Filtration, Inc. 615/821-4022 x. 651
jim@tiamat.fsc.com ( IT Manager) (02/22/91)
The drives mentioned in my original article are now running under SCO Unix 3.2v2 and they all have AFS file systems on them. Below are some updated numbers on their performance. During the installtion, I made the Micropolis drive the /usr/local and /usr/spool drive, and it seems to handle having lots of little files (e.g. /usr/spool/news) better than the Miniscribe did. But, then again, this could be due to the AFS filesystem. In article <790@tiamat.fsc.com>, jim@tiamat.fsc.com ( IT Manager) writes: > As far as performance goes, here's some numbers: > > from "time dd if=/dev/XXXX of=/dev/null bs=100k count=10" > > for the Miniscribe 3180S > 10+0 records in > 10+0 records out > > real 17.7 > user 0.0 > sys 0.4 under Unix: real 3.0 user 0.0 sys 0.2 > for the Miniscribe 8380S > > real 17.9 > user 0.0 > sys 0.5 under Unix: real 3.0 user 0.0 sys 0.3 > for the Micropolis 1684 > 10+0 records in > 10+0 records out > > real 3.9 > user 0.0 > sys 0.6 under Unix, /usr/spool filesystem: real 11.1 user 0.0 sys 0.4 /usr/local filesystem: real 6.9 user 0.0 sys 0.4 From the looks of those numbers, it seems that the data you have on the drive (or how it is arranged) can have something to do with the performance under this type of test. > On the surface (and definitely under this installation) the Micropolis is > much faster. These drives are are installed in their "default" state, so > there has been no performance tuning. These drives will be involved in an > upgrade soon, and before we install the OS, I'll use Roy Neese's SCSICNTL > program to try to do some fine tuning on the drives. Well, I tried to use SCSICNTL but kept getting message about not being able to read something from the adapter. Oh, well. So, the only configuring I did was to re-format these drives using the Adaptec on-board BIOS routines and specify a 1:1 interleave. All in all, I still like the SCSI drives and I like them even better under Unix. ------------- James B. O'Connor jim@tiamat.fsc.com Ahlstrom Filtration, Inc. 615/821-4022 x. 651
bill@unixland.uucp (Bill Heiser) (02/23/91)
In article <797@tiamat.fsc.com> jim@tiamat.fsc.com ( IT Manager) writes: >> >> from "time dd if=/dev/XXXX of=/dev/null bs=100k count=10" >> >> for the Miniscribe 3180S >> 10+0 records in >> 10+0 records out >> >> real 17.7 >> user 0.0 >> sys 0.4 > >under Unix: >real 3.0 >user 0.0 >sys 0.2 > >From the looks of those numbers, it seems that the data you have on the >drive (or how it is arranged) can have something to do with the performance >under this type of test. This is interesting. I tried reading several different partitions (/dev/dsk/0s0, /dev/dsk/0s1, /dev/dsk/0s3, etc), and all came out about like this: Script started on Fri Feb 22 17:49:25 1991 # sh # time dd if=/dev/dsk/0s3 of=/dev/null bs=100k count=10 10+0 records in 10+0 records out real 7.6 user 0.0 sys 1.5 # # script done on Fri Feb 22 17:49:47 1991 This is on a 386/25 running Esix-D. /dev/dsk/0s3 is my /usr partition (where about 100mb worth of Usenet News is sitting). The disk is a CDC Wren IV (94171-307). Your "real time" numbers seemed to vary from 3.0 to 8.0 -- Mine seemed to stay about the same. Maybe system loading, different buffer cache size, or some other factor? Bill -- home: ...!{uunet,bloom-beacon,esegue}!world!unixland!bill bill@unixland.uucp The Think_Tank BBS & Public Access Unix 508-655-3848 (2400) 508-651-8723 (9600-HST) 508-651-8733 (9600-PEP-V32) other: heiser@world.std.com