Path: utzoo!attcan!uunet!lll-winken!lll-tis!ames!mailrus!tut.cis.ohio-state.edu!mandrill!hal!ncoast!allbery From: allbery@ncoast.UUCP (Brandon S. Allbery) Newsgroups: comp.unix.wizards Subject: Re: Vax 11/780 performance vs Sun 4/280 performance Message-ID: <7944@ncoast.UUCP> Date: 10 Jun 88 01:26:48 GMT References: <14968@brl-adm.ARPA> <601@modular.UUCP> <7331@swan.ulowell.edu> <2282@rpp386.UUCP> Reply-To: allbery@ncoast.UUCP (Brandon S. Allbery) Followup-To: comp.unix.wizards Organization: Cleveland Public Access UN*X, Cleveland, Oh Lines: 46 As quoted from <2282@rpp386.UUCP> by jfh@rpp386.UUCP (John F. Haugh II): +--------------- | 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. +--------------- The P/55 has a dumb SMD controller, unless you bought the EMSP, which is a smart SMD controller identical to that used on at least some Sun-3's. Query: how did you calculate load average? Is the P/95 *really* ESDI? I thought they used a VMEbus Xylogics SMD... but I don't really know that much about the '95. 4MB RAM is not the best way to run if you have 10 users. This is from experience. You swap *way* too much under SVR2, experience with 2MB on a 386 box with SVR3.1 and 8 heavy database users shows way too much paging. P/60 with 12.5MHz 68020, multibus, 7MB RAM, EMSP (Xylogics 451 SMD) disk interface: ran 18 users at a load average (courtesy my /etc/avenrun) of 2. [Note that I've never been certain of the reliability of /etc/avenrun as compared to BSD, since the actual code isn't mine and *definitely* isn't in the kernel where it should be to be accurate.] No problems whatsoever; lots of DBMS, some WP and at least one C compile -- often two concurrent (that was me ;-) and the system still responded quite well. Usage has changed since I left the company that has that configuration; I can check on the current statistics. (N.B. The configuration described above is actually a P/60 which has been upgraded to a P/75, except for the serial/parallel I/O controllers.) As for the 386 box mentioned above: at 4MB, 8 users all doing database (or 7 users doing database and one compile, again me), it *said* that the kernel load average was 72. The "load average" it reports, however, seems to be not what we usually deoad abverage; you have to divide by the number of processes, typically 75-80 = load average slightly less than 1. Performance? Let's put it this way: at full load, it was faster than ncoast (68000, 2MB RAM, dumb SMD controller: P/35) with *one* user. -- Brandon S. Allbery | "Given its constituency, the only uunet!marque,sun!mandrill}!ncoast!allbery | thing I expect to be "open" about Delphi: ALLBERY MCI Mail: BALLBERY | [the Open Software Foundation] is comp.sources.misc: ncoast!sources-misc | its mouth." --John Gilmore