henry@utzoo.UUCP (Henry Spencer) (09/06/84)
I'm posting the following for a friend whose machine doesn't get news.
Note that he won't see followups; reply by mail, please. Also note
that you should reply to him, not me.
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Our VAX780 has ongoing problems with getting swamped at between 28 and 30
interactive users with a 4 job batch load. We have monitored consumption
of CPU and determined that CPU utilization is between 60 and 70 percent.
Attempts at tuning (adding memory and increasing working set sizes) has
produced little improvement. Management has interpreted the CPU utilization
numbers and determined there must be something wrong with our tuning effort.
(It seems they've read the DEC Propaganda about being able to support
60 users on a 780...).
Our environment is predominantly software development with some text
processing. We have an RM05 system disk and a FUJI EAGLE disk that stores
our user files, we have oodles of memory (6Meg), with usually 2000 pages to
spare (even when the system is "swamped"). Oh, yeah, we run VMS (but we
*DO* have a Unix emulator that most of the non-plebs use...).
What I'm interesting in is any documentation or studies that have been done
to show *realistic* performance expectations from the VAX family under
various loads/job mixes. Plain benchmarks aren't really all that useful
and would be of little value. "Real life" benchmarks and performance
evaluations would be quite useful.
Thanx in advance,
Marcus Leech
Gandalf Data Ltd,
decvax!hcr!gandalf!ml
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