Path: utzoo!attcan!uunet!comix!jeffl
From: jeffl@comix.UUCP (Jeff Liebermann)
Newsgroups: comp.unix.sysv386
Subject: Re: Take out memory to speed up kernel build!?
Summary: 16 bit RAM ?
Message-ID: <78@comix.UUCP>
Date: 3 Oct 90 08:42:45 GMT
References: <34417@cup.portal.com>
Organization: COmmittee to Maintain Independent Xenix
Lines: 24

In article <34417@cup.portal.com>, ts@cup.portal.com (Tim W Smith) writes:
> I've got 4 megs of RAM, and the command /etc/conf/cf.d/link_unix
> takes about 7.5 minutes.
> When my back was turned the other day, one of our QC people
> stole my memory card, leaving me with only 2 meg.
> Guess what?  My kernel build now takes only 5 minutes!

If you could pull 2 Mb out on a single card, it must
be a 16 bit memory card plugged into the AT bus.  The bus probably
runs at 8Mhz while the CPU and the main memory runs at 20-25Mhz.
Since Unix runs it's kernel in high memory where the 16bit 8mhz
slow RAM previously resided, removing the slow ram forced the
kernel into faster (20-25Mhz) ram.

I've made lots of assumptions here, but I've seen this before when
RAM was expensive and Unix was simultaneously growing.   The related
part that irritates me is that it take 4Mb of RAM to install SCO
Unix, but only 2Mb to run it.

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