farhad@corwin.usc.edu (Farhad Khansefid) (03/07/88)
Thanks to those who responded to my query. I basically wanted to know how far can one push a 386 machine running xenix and what are the limiting factors (disk space, ram, multi serial ports ...etc.) to consider. Following is an edited summary of the responses I got. ( By the way, I am still very much interested in hearing your comments and experiences in using a 386 machine running sco xenix. Please mail to farhad@corwin.usc.edu and i will summarize again if necessary.) ====================== FROM: Dean Brunette at oliveb!olivej!dragon@ames.arc.nasa.gov SYSTEM: 20mhz 386 machine running SCO XENIX, 8Meg RAM , 2 AST 4-port cards. I have Up to five users running on it with no great performance degradation, until they started doing CPU or disk intensive tasks. I think two important things that improve performance are: high performance drives (you'll notice a *big* increase in speed with an 18ms drive over a 28ms, and if you have two different drives that will help too), and lots of RAM (I have 8 megs, and it's not enough for 8 users... the thing was terribly slow with only 4 megs). I have 8 serial ports on the beast without using smart ports yet (two AST 4-port cards). ===================== FROM: James R. Van Artsdalen !uunet!utastro!bigtex!james@astro.as.utexas.edu SYSTEM: ? The limiting factor in unix (or xenix) performance is not really any of the factors you mentioned, but the amount of RAM in the system. Put in 2meg + 512K / light-user or + 1meg for a heavy user. ===================== FROM: Paul Lucchina at hsi!lucchina@uunet.UU.NET SYSTEM: [will purchase] Compaq 386/20 with a 300 Mb disk / 5 Mb of memory. We will be running Santa Cruz Xenix 386 OS. Santa Cruz refered me to a consuting firm in Hartford, CT. They have integrated 32 user systems utilizing this config. The consultants at this firm are real purists and have given me a lot of tips on getting the maximum performance out of this box. Here are some of them: If you don't need the monochrome display and adapter for console don't bother purchasing on. It is a hog on interrups and you can install SCO from the com ===================== FROM: Robert Boucher at sco!robertb@uunet.UU.NET SYSTEM: 286 Even though the company [sco -ed.] probably has some "official figures," the group that I'm in is currently running 11 users on a 286. The machine gets sluggish sometimes (when people start running informix :-(), but it serves us well... (Just to add to the figures, our group is doing simple things like reading mail, news, occasional compiles, etc.) ======================= From: Andrew Beattie <ames!lll-lcc!uunet!mcvax!sphinx.co.uk!andrew%ll-xn.UUCP@oberon.usc.edu> SYSTEM: some compaq 386/16 with 130Meg, will gte 386/20 with 300Meg. Chase AT8 > > - How does the performance degrade compared > to a one or two user system? > Not much different - still impressivly fast > > - Did you have to use Smart serial ports? > Yes - Chase AT8, but now we go in by TCP/IP using an Excelan Board > > - How far do you think one can push a 386? > I would Guess at about 16 or more, if you have lots of memory but try as we might we never seem to overload the machine (I am in a department of 10 Techies running a 4GL database and all the products we have to support) ) > > - Would 28ms disk access time be sufficient > or you need to spend some buck for 18/16.5 ms? > Dunno - we run several Compaq 386/16 with 130Meg disks (we are getting a 386/20 with 300Meg real soon now) ====================