lars@ACC.ARPA.UUCP (05/13/86)
> Date: Mon, 12 May 86 16:23:23 -0100 > From: "Stephan Wasserroth" <unido!vax.hmi.dfn!wasserroth@seismo.CSS.GOV> > To: info-vax@sri-kl.arpa > Message-Id: <83:wasserroth@vax.hmi&dfn> > Subject: Measuring response time > > On interactive systems like VAX-computers the "response time" is an important > measure for the actual workload of the system. Everybody feels unhappy, if > the response time is high (me too). But it is difficult, to measure the > response time of a CPU. Normally the idle-time is taken as a measure for > the current load on a computer. > > Now the question: Do *You* have an idea, how to determine a value describing > the current response time on a computer? Or do *You* have a program for this > purpose? > > Stephan Wasserroth / VAX System Manager > Hahn-Meitner-Institut / Glienicker Str. 100 / D-1000 Berlin 39 > ARPA: <unido!vax.hmi.dfn!wasserroth@seismo.css.gov> Actually, the idle time is not very interesting, once it drops to ZERO. So long as there is some idle time, the system is not really loaded down (unless you are disk bound and/or page thrashing), but once you get the CPU filled up, the load starts stacking up. A good measure for heavy loads seems to be the LOAD AVERAGE, defined as the average number of ready-to-run processes. Typically measured over one minute, 5 minutes and 15 minutes. The EUNICE package from Wollongong contains a pseudo-device-driver which gives you these three figures. When your load average goes above 5, you probably have already discovered that the system is heavily loaded ... / Lars Poulsen Advanced Computer Communications <Lars @ ACC.ARPA> ------