Path: utzoo!dciem!nrcaer!scs!spl1!laidbak!att!osu-cis!killer!vector!rpp386!jfh From: jfh@rpp386.UUCP (John F. Haugh II) Newsgroups: comp.unix.wizards Subject: Re: Vax 11/780 performance vs Sun 4/280 performance Message-ID: <2282@rpp386.UUCP> Date: 1 Jun 88 18:13:41 GMT Article-I.D.: rpp386.2282 References: <14968@brl-adm.ARPA> <601@modular.UUCP> <7331@swan.ulowell.edu> Reply-To: jfh@rpp386.UUCP (The Beach Bum) Organization: Big "D" Home for Wayward Hackers Lines: 31 In article <7331@swan.ulowell.edu> arosen@hawk.ulowell.edu (MFHorn) writes: >In article <601@modular.UUCP> olson@modular.UUCP (Jon Olson) writes: >> there is a knee in the performance curve of the Sun-4/280 at > 15 processes >> And the Sun-3's are no better: the knee there is >7 processes. > >Some time ago I saw a Sun 3/280 with a load average of 17+. There were >17 'extra' jobs running. I don't know what they were doing (they weren't >mine), but there was no [noticable] degradation in response time at all. our plexus p/95 (20MHz 68020, vme bus, 8MB ram, esdi controller) knees at about 20 users with a load average of 10+. on the few occasions the machine has been to 13+ it has crashed shortly thereafter. the p/55 (12.5MHz 68020, multi bus, 4MB ram, scsi? controller) knees at about 10 users. i don't know the load average off hand but it has been up around 10 without crashing. it just gets painfully slow. i suggest the Big Problem is with the disk/controller combinations. my '386 can't run an expire and an rn together because the disk saturates. same seems to be true with the plexus machines. the p/55 has a single controller and a single drive. the p/95 has a single (faster) controller with two drives. once the i/o on either plexus is saturated (the famous popcorn noise is my general working definition), regardless of the number of processes, adding one more serious dogs the system. - john. -- John F. Haugh II | "If you aren't part of the solution, River Parishes Programming | you are part of the precipitate." UUCP: ihnp4!killer!rpp386!jfh | -- long since forgot who DOMAIN: jfh@rpp386.uucp |