Path: utzoo!attcan!uunet!lll-winken!lll-lcc!ames!elroy!cit-vax!mangler
From: mangler@cit-vax.Caltech.Edu (Don Speck)
Newsgroups: comp.unix.wizards
Subject: Re: Vax 11/780 performance vs Sun 4/280 performance
Summary: context switch rate
Message-ID: <6820@cit-vax.Caltech.Edu>
Date: 5 Jun 88 08:45:49 GMT
References: <15875@brl-adm.ARPA> <2360@umd5.umd.edu>
Organization: California Institute of Technology
Lines: 10

In article <15875@brl-adm.ARPA>, weiser.pa@xerox.com writes:
> Perhaps the 50ms. sleeper test is a red herring, and that pathological state is
> not one that is ever seen under normal user loads.

When I started using 4.3 BSD /etc/dump with two tape drives on this
780, I was getting 250 context switches per second among 8 processes.

For another curious VAX/SUN comparison, notice how pipes on Sun-3's run
half as fast when the buffer address is odd.  No such penalty on vaxen.

Don Speck   speck@vlsi.caltech.edu  {amdahl,ames!elroy}!cit-vax!speck