Path: utzoo!utgpu!cunews!bnrgate!bnr-fos!bmers145!bmerh140.bnr.ca!larryd
From: larryd@bmerh140.bnr.ca (Larry Dunkelman)
Newsgroups: comp.sys.dec
Subject: DEC 582810/20 performance concerns
Message-ID: <1990Nov1.050433.5615@bmers145.bnr.ca>
Date: 1 Nov 90 05:04:33 GMT
Sender: news@bmers145.bnr.ca
Reply-To: larryd@bmerh140.bnr.ca (Larry Dunkelman)
Organization: BNR Ottawa, Canada
Lines: 30

After reading a number of postings concerning the performance of the
5810/20 I realized I wasn't alone in wondering why these machines seem
to run slower than the supposedly slower 3100.

I ran a benchmark to compare the performance of 5810 with a 3100.
The 5810 was configured with 256 MB of memory and 6 RA90 drives connected
via an HSC.

The 3100 had 8 MB of memory and 2 SCSI disks.  

I tested the "raw" CPU power, (no disk I/O and limited memory access) and
found that the 5810 was about 30% faster than the 3100 (as expected since
the 5810 uses the faster R3000 processor).

I then ran a memory test which involved an enormous amount of memory 
access (the program built a linked list by scanning the list until the
end was reached and then adding the list element - 5000 times!).  

The results of this last test were very suprising.  The 3100 ran the
benchmark in 29 seconds.  The 5810 took 67 seconds.  These times were
CPU usage (real time was the same as there was no other system activity).

DEC acknowledged the problem with the memory on the 5800 series but said
they were not planning on doing anything about it. I gave DEC my program
about 4 months ago -- no word since then.

I'll save the rest of my experiences with the 5800s (yes, I have two of 
them -- and have plans to buy two more) and ULTRIX 4.0 for later.

Larry.