elg@killer.DALLAS.TX.US (Eric Green) (05/26/89)
My setup: Amiga 500 with 1 meg of RAM
Subsystem 500
C LTd. "Kronus" SCSI controller.
Seagate ST157N 48 mb drive, 40ms
Results:
File create/delete: create 11 files/sec, delete 22
Directory scan: 106 entries/sec
Seek/read test: 112 seek/reads per second.
Buffer Read Write
1024 128923 104163
8192 268865 144964
32768 383625 218453
65536 476625 268865
131072 499321 317750
262144 507375 338250
Comments: the Kronus is VERY sensitive to what else is taking up the
CPU. The above diskperf was taken by using the standard startup CLI,
with nothing else (conman, qmouse, mclock) running. I didn't even have
my second drive hooked up, on the theory that the additional
trackdisk.device would take up CPU cycles the controller could
otherwise use. Even running conman drops the performance down
slightly (to about 501K). Running qmouse and mclk, and configuring my
machine the way I usually run it (two floppies, heavily overscanned
interlaced screen) drops the top end down to 450K, and the rest of the
numbers proportionally less (note: because smaller buffers aren't as
CPU intensive, they aren't as much affected by multitasking).
I used an 8mb DH1:, totally empty and freshly formatted, to tweak my
diskperf. I got the best results with 32 AmigaDOS buffers and 16
DevSetUp buffers. More AmigaDOS buffers helped with small requests,
for some reason, but detracted from top end. More device driver
buffers similiarly didn't help... I tried 10, 12, 16, 20, 32, and
after 20 the performance similiarly dropped.
Naturally I don't usually run my computer from a bare CLI. I wanted to
test C Ltd's claim (before I bought their controller to go with my
hard drive) that their controller would do 500k/second with my hard
drive. It does. But at a terrible cost. Still, I can't exactly claim
they lied :-}.
C Ltd claims that, with a faster drive, they can get sustained
600k/second transfers out of the Kronus. I can believe that, since the
157N isn't exactly a CDC Wren. They also claim that with a 68020 and
the Kronus, they can get 1 MEGABYTE per second transfers. Considering
that running out of CPU seems to be what slows down the transfers, I
can believe that, too. A 68020 running out of 32 bit RAM can probably
fetch bytes from the Kronus about as fast as a DMA controller could
shove bytes into 32 bit RAM.
You might view the Kronus as C Ltd's answer to the GVP Impact. The
main reason I bought it is because of rumors of problems with DMA disk
controllers in external expansion chassis. It is slower than, e.g., a
Supra DMA controller (which seems to be the fastest around in normal
use, from the diskperf #s I've seen, but damn, what lousy software!),
but presumably will run reliably in my Subsystem 500. I say
"presumably", because my setup has locked up 3 or 4 times a day with
the green light stuck on and the only way to reset being to turn off
everything... but I think I traced that problem down to the cabling. I
re-worked the cabling... the rest, only time will tell.
--
Eric Lee Green P.O. Box 92191, Lafayette, LA 70509
..!{ames,decwrl,mit-eddie,osu-cis}!killer!elg (318)989-9849
bcase: "I have seen or heard 'designer of the 68000' attached to so many
names that I can only guess that the 68000 was produced by Cecil B. DeMile.""kosma@ALAN.LAAC-AI.Dialnet.Symbolics.COM"@alan.kahuna.decnet.lockheed.com (05/31/89)
Received: from BLAISE.LAAC-AI.Dialnet.Symbolics.COM by ALAN.LAAC-AI.Dialnet.Symbolics.COM via CHAOS with CHAOS-MAIL id 23699; Fri 26-May-89 09:44:35 PDT
Date: Fri, 26 May 89 09:43 PDT
From: Montgomery Kosma <kosma@ALAN.LAAC-AI.Dialnet.Symbolics.COM>
Subject: Re: Diskperf results: C Ltd. Kronus
To: "eagle::amiga-relay%udel.edu"@KAHUNA.LAAC-AI.Dialnet.Symbolics.COM
In-Reply-To: Your message of 26 May 89 03:02 PDT
Message-ID: <19890526164348.3.KOSMA@BLAISE.LAAC-AI.Dialnet.Symbolics.COM>
My setup: A2000 / 3 megs total RAM
A2090 (NOT 2090A, unfortunately)
Seagate ST251 40 MB/28ms drive (ST506)
^^^^ not positive about this number...might be 40ms
I've just recently acquired DiskPerf...I've been trying to tune my setup for
optimum HD speed (FFS). Could somebody post/Email data on what numbers I should be
expecting from DiskPerf? (I don't have my numbers available) Also, any info on
best settings (or how to determine best settings) for buffers, MaxTransfer, etc,
would be quite useful. The AmigaDOS 1.3 manual is unfortunately somewhat sparse
when it comes to discussing mountlist parameters in detail...
Thanks!
monty kosma