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Date: Tue, 14 Mar 1995 17:25:18 -0800
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To: richard@cogsci.ed.ac.uk
CC: kargl@troutmask.apl.washington.edu, davidg@Root.COM, phk@ref.tfs.com,
        freebsd-hackers@freefall.cdrom.com
In-reply-to: <199503141434.OAA03371@deacon.cogsci.ed.ac.uk> (message from Richard Tobin on Tue, 14 Mar 1995 14:34:29 GMT)
Subject: ROT (Re: install compressed binary patch)
From: asami@cs.berkeley.edu (Satoshi Asami/=?ISO-2022-JP?B?GyRCQHUbKEI=?= =?ISO-2022-JP?B?GyRCOCsbKEIgGyRCOC0bKEI=?=)
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 * This and similar rules of thumb are the wrong way round.  The amount of
 * swap space you need is not determined by how much RAM you have!  Rather,
 * then amount of swap space is determined by what programs you want to
 * run simultaneously, and you should have as much RAM as possible up
 * to that amount.

Of course you are right, but don't forget RAM is (very) expensive.
The reality is that, people usually have a fixed budget (i.e., fixed
amount of RAM) and want to see what they can do with it.

 * Of course, things will be slooow if you don't have enough RAM, so a
 * rule of thumb might be to have at least half as much RAM as swap.  But
 * note that if you translate this to swap in terms if RAM, it says that
 * 2 * RAM is a *maximum* amount of swap, not a minimum or a
 * recommendation.

As I understand, the "rule of thumb" says that if you could afford X
MB of RAM, you might as well make good use of it by allocating 2X MB
of swap (disk is cheap anyway).  And having much more than 2X MB of
swap is usually useless, 'cause if you're running that many programs
with only X MB of RAM, your machine will slow down to the speed of a
injured turtle....

Satoshi

P.S. I personally have 20 MB of RAM and 64 + 32 MB of swap (two
     disks).  Yes, my machine is soooooooooooooo slow when I try to
     run too many things but I figured it's still better than crashing
     or killing some process....