From: ws@xivic.bo.open.de (Wolfgang Schelongowski) Subject: Re: SCSI Performance (Yet Again) Date: Wed, 25 Aug 1993 12:18:47 MEST
bill@yossarian.ucsd.edu (Bill Reynolds) writes:
> In article <u5oq9B1w165w@xivic.bo.open.de> ws@xivic.bo.open.de (Wolfgang Sche
>
> How about
> date;dd if=/dev/sda of=/dev/null bs=131072 count=512;date
> (This does only a read, you have to save and restore via dd
> if you want to test write. Just be _very_ careful about _where_
> you test ! Maybe you should backup the disk.)
>
> That took 69 seconds => 950 KByte/sec for raw I/O. Under BSDI,
> the numbers are 36 seconds on /dev/rsd0a => 1820 KByte/sec.
>
> Hmm.. I don't know what my problem is. 486/66 clone AHA1742, 1G
> Fujitsu disk, in extended mode with 32M of main memory on an EISA bus,
> I get 261s for the above command => 257 KByte/sec.
> I'm running Linux yossarian 0.99.11 #3 Tue Jul 6 18:58:52 MDT 1993 i486
>
> (Wait a sec, as your humble narrator tries some stuff).
>
> Ok, the above was done with X and term running (interrupts up the
> wazoo!). Killing all extraneous processes, I get 61s => 1100 Kb/sec -
> much better! So it's obvious that these benchmarks depend on a lot
> more than just disk/bus speed.
I did my test without X. I even killed lpd, and the network daemons
always show 0:00 on ps ax as this is a standalone machine.
But _you_ use an _EISA_ machine with a _1742_ in extended mode
and a (supposed) M2694ESA/SA/FA. You should get a much better
throughput than a mere 115% of mine.
As this group expires soon (probably no longer read by the
developers anyway) AND you have a rather up-to-date release
0.99.11 against my 0.99.6 AND a real fast hardware, could you
please alert the developers of the SCSI- and SCSI-disk-driver ?
They ought to be interested in a possibly 200% speed increase.
I'm available for e-mail discussion about this subject until
I go on holiday.