What advantage is extra memory?

[Thad P Floryan]

It appears everything in and out of PORTAL between Dec.14 and Dec.17 has been
lost in the Great Bit Bucket.  I've checked several other Bay Area sites and
did not find this, so I'm reposting.  Sigh.  If the original did, somehow,
get out during that period, send your nastygrams to CS at cup.portal.com ("CS" is
PORTAL's "Customer Service").
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jon at jonlab.UUCP (Jon H. LaBadie) in <896 at jonlab.UUCP> writes:

	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?

Faster compiles, less swapping, better overall system throughput.

	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?

More memory will reduce the likelihood of the kernel downgrading some of your
tuning parameters.

	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?

You better either use the combo card tty ports (OR) upgrade to at least the
3.51a kernel ... many tty000 (on-board RS-232 port) serial port bugs were fixed
in 3.51a (like, with BREAK handling, etc.)

Thad Floryan [ thad at cup.portal.com (OR) ..!sun!portal!cup.portal.com!thad ]