On Thu, 5 Jun 1997 10:47:22 -0600  Michael L. Hitch wrote:

> On Jun  5,  6:57pm, Takuya Koumoto wrote:
> > I got the recent source code(approximately 1997/6/5) and
> > build the new kernel on DEC5000/25 with 40MB of memory and
> > an RZ25(400MB) HDD. The iozone gives the following results
> > on 100MB sequential I/O test. Thanks to Mr. Nishimura, the
> > old kernel(2 months ago) gave 1.6MB/sec for writing. Is that
> > a known problem?
> > 
> >         347844 bytes/second for writing the file
> >         1360373 bytes/second for reading the file
> >         350038 bytes/second for writing the file
> >         1322456 bytes/second for reading the file
> >         349362 bytes/second for writing the file
> >         1337128 bytes/second for reading the file
> 
> Hmm - on my DS5000/25 and an RZ25 (but using a 99MB file), I get:
> 
>         1255855 bytes/second for writing the file
>         1337400 bytes/second for reading the file
> 
> This is with a kernel built from sources around May 29 (and I don't know of
> any significant changes since then).  This was with the DS5000_25 config
> file with the DEBUG option enabled.
> 
> I don't know why you would be seeing such a low write performance.
> 
> Michael

As another data point, I've got a 5000/240 with a RZ26N, and I get these
figures with IOZONE:

	393461 bytes/second for writing the file
	1757389 bytes/second for reading the file

and from bonnie:

              -------Sequential Output-------- ---Sequential Input-- --Random--
              -Per Char- --Block--- -Rewrite-- -Per Char- --Block--- --Seeks---
Machine    MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU  /sec %CPU
mona       20   522 33.4   520  4.9   417  6.2  1032 98.0  1773 17.5  58.5  5.0

This is on a machine with 40MB memory and 4MB of buffer cache.  On a
similar box (5000/240, 32MB RAM, 6.4MB buffer cache, RZ26N) running
Ultrix 4.4, I get these results for IOZONE:

	1853201 bytes/second for writing the file
	2612520 bytes/second for reading the file

and bonnie:
              -------Sequential Output-------- ---Sequential Input-- --Random--
              -Per Char- --Block--- -Rewrite-- -Per Char- --Block--- --Seeks---
Machine    MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU  /sec %CPU
nsw085     20  1084 98.3  1773 25.2  1245 34.6   989 94.3  2820 42.8  80.0 14.3

Seems the SCSI driver isn't as fast as it could be...

Simon.