Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!cs.utexas.edu!uunet!crdgw1!crdos1!davidsen
From: davidsen@crdos1.crd.ge.COM (Wm E Davidsen Jr)
Newsgroups: comp.unix.i386
Subject: Re: Cache performance on 386 boards running Unix
Message-ID: <1508@crdos1.crd.ge.COM>
Date: 27 Oct 89 18:27:46 GMT
References: <919@umigw.MIAMI.EDU> <416@ssp2.idca.tds.philips.nl> <1989Oct27.031800.4938@ico.isc.com>
Reply-To: davidsen@crdos1.UUCP (bill davidsen)
Organization: GE Corp R&D Center
Lines: 25

In article <1989Oct27.031800.4938@ico.isc.com>, rcd@ico.isc.com (Dick Dunn) writes:

|  Some informal experiments we've done suggest that a decent cache does a lot.
|  For example, a cached 25-MHz machine is easily twice as fast as an uncached
|  16-MHz even though the processor is only about 50% faster.

  It really does depend on the machine, not just the speed. For instance
a machine with 2 and 4 way interleave would benefit less from a cache
than one with no interleave, and one with wait states benefits more than
one without. 16MHz is the point at which it is still possible to do 0w/s
with more or less standard memory parts.

  I have done some measurements on normal, interleaved, and 16 bit
memory, and conclude that cache is a huge win as your memory gets
slower, and that 64k will mask the effects of slow memory for many
applications.

  note: I'm note disagreeing, just adding some clarifying information. I
would not buy a 25/33 MHz machine w/o cache, because it adds so little
to the price of the machine as a whole ($200-300).
-- 
bill davidsen	(davidsen@crdos1.crd.GE.COM -or- uunet!crdgw1!crdos1!davidsen)
"The world is filled with fools. They blindly follow their so-called
'reason' in the face of the church and common sense. Any fool can see
that the world is flat!" - anon