Path: utzoo!attcan!uunet!husc6!bloom-beacon!gatech!emcard!sdba!stan
From: stan@sdba.UUCP (Stan Brown)
Newsgroups: comp.unix.wizards
Subject: Re: Vax 11/780 performance vs Sun 4/280 performance
Message-ID: <264@sdba.UUCP>
Date: 31 May 88 17:32:33 GMT
References: <14968@brl-adm.ARPA>
Organization: S. D. Brown & Assoc.  Atlanta, Ga
Lines: 22
Posted: Tue May 31 13:32:33 1988

> What your DEC salesperson may have heard, undoubtedly very indirectly, is that
> there is a knee in the performance curve of the Sun-4/280 at > 15 processes
> ready-to-run.  This has nothing to do with > 15 users: more like a load average
> of > 15.  Do your vaxes ever run with a load average of > 15?  If not, ok.  But,
> if they EVER hit 16 or 17, watch out on the Sun-4's:  I can trivially get my
> Sun-4 completely wedged so I have to reboot with L1-A by just starting 19 little
> processes which sleep for 100ms, wake-up and sleep again.  This doesn't even
> raise the load average (but amounts to a load average of 19 to the context
> switching mechanism, although not to the cpu).
> 
> And the Sun-3's are no better: the knee there is >7 processes.
> 
> -mark

	Realizing that if this *is* true on the RoadRuner it will be
	true at a much lower number, does anyone know if such a thing
	is true on it ?


-- 
Stan Brown	S. D. Brown & Associates	404-292-9497
(uunet gatech)!sdba!stan				"vi forever"