[comp.unix.xenix] Big Disk Advice Requested

rfarris@serene.UUCP (Rick Farris) (02/15/90)

I am considering the purchase of a large (600 - 700 Mb) hard-drive,
and an esdi controller.  I'd appreciate any comments that you may
have. 

I've pretty much decided on a WD 1007 controller, but I notice that
there are several versions around.  I understand that some come with
a built in floppy controller and some don't, but there seem to be
more than two versions.  I've seen them advertised with "dual 8k
caches," and also with "32k cache."  I think that what I want is a
WD1007?-SE2, should the ? be an A or a V?  I want the fastest/best
one (vs. the fastest/cheap one), would someone point me in the right
direction? 

I'm considering a CDC Wren VI 660 Mb drive.  Does anyone have any
comments on the suitability of this drive with the 1007 controller
for use under SCO UNIX?

I've seen 660 Mb Wren VIs and 620 Mb Wren Vs -- other than 40 Mb,
what is the difference between them?

Am I overlooking anything?  Any general advice?


Rick Farris   RF Engineering  POB M  Del Mar, CA  92014   voice (619) 259-6793
rfarris@serene.uu.net      ...!uunet!serene!rfarris       serene.UUCP 259-7757

richard@neabbs.UUCP (RICHARD RONTELTAP) (02/18/90)

[ WD1007 and big disks ]
 
We recently installed an WD1007SE2 (wich means: with floppy
controller) and a Micropolis 780 MB ESDI disk. (unformatted, can't get
at de model number right now).
 
Initially the disk gave an amazing thoughput of 50 kb/sec. 
The supplier then suggested to format the disk at 53 sectors per
track, in stead of 54. That helped, the throughput is now 350 kb/sec
with the command:
dd if=bigfile of=/dev/null
 
Note that bigfile is an ordinary file, not a device. No part of the
file was in the XENIX cache, and the cache (read ahead on the WD 1007
was enabled.
 
I installed SCO's WD1007 fix (xnx133) just to be safe, but I didn't
have any problem with the drive before I installed the patch. Does
anybody know what the patch is for exactly, and which controller
revisions need it. The info with the patch says nothing, I thought I
read here it had something to do with the readahead cache on the WD.
 
Now the reason for this posting is:
 
Is 350 kb/sec an acceptable throughput? Has anyone got better? I read
the WD1007 has a full track buffer, but what track length is assumed
for that. 53 sectors (26.5 Kb) maybe is too large for the buffer. A
controller with a larger cache might do better.
 
I can't RTFM because we didn't get one with neither the disk nor the
WD1007.
 
Richard
(...!hp4nl!neabbs!richard)