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Path: utzoo!utgpu!watserv1!watmath!uunet!wuarchive!udel!princeton!jonlab!jon
From: jon@jonlab.UUCP (Jon H. LaBadie)
Newsgroups: unix-pc.general,comp.sys.att
Subject: What advantage is extra memory?
Keywords: 3b1 combo card ktune performance tuning tty ports
Message-ID: <896@jonlab.UUCP>
Date: 15 Dec 90 06:57:16 GMT
Followup-To: unix-pc.general
Organization: 4455 Province Line Rd., Princeton, NJ 08540
Lines: 34

I'm running a UnixPc with 2 Mbyte of memory (67 Mbyte drive).
I've also got the DOS-73 card and the 23 Mbyte tape drive.
The O.S. is stock 3.51, no FixDisk upgrades.

I just acquired a combo card with 1.5 Mbyte additional memory.

Three questions related to performance:

1. What if any performance inprovements should I expect by having
   the 75% greater total memory?

2. I figured that I/O might benefit by having more disk buffers etc.
   so I used ktune to increase nbuf (100 -> 200), clist, and one
   other parameter.  To my surprise, 6 tunable parameters were
   affected by my ktune command.  The 3 increases I requested were
   partially implemented (ex. nbuf went to 150 rather than 200 as
   requested) but 3 other parameters were decreased (ex. nproc and
   nfile).

   Any comments on what is going on here?  And what are good choices
   for the tunable parameters with 3.5 vs. 2.0 Mbytes memory?

3. I'm using an external 2400 baud modem (thanks Pete).  Any reason
   to consider switching to the combo card tty ports rather than the
   builtin tty port for this device?

Thanks for sharing your collective experience.

Jon


-- 
Jon LaBadie
{att, princeton, bcr, attmail!auxnj}!jonlab!jon