Path: utzoo!attcan!uunet!tut.cis.ohio-state.edu!ucbvax!RICHTER.MIT.EDU!krowitz
From: krowitz@RICHTER.MIT.EDU (David Krowitz)
Newsgroups: comp.sys.apollo
Subject: Re: standard SIMMs in s400?
Message-ID: <9009191403.AA24454@richter.mit.edu>
Date: 19 Sep 90 14:03:55 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
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Oddly enough, Sun seems to be able to use PC SIMMS in the Sparcstation 1
and 1+ to achieve the sort of performance levels that HP is hoping to
hit (15 to 20 MIPS) when the 68040 chips become available. It's also
odd that the message refers to 64 bit data paths, at the sales literature
I have been given by our HP sales office states that the bus width is
32-bit data/32-bits address ("HP Apollo 9000 Models 400s and 433s
Technical Data", July 1990). 4 PC SIMMS installed in parallel as they
are in the DN2500, Sparcstation 1/1+, and other machines provides the
same 32-bit data path. As for the ECC ... yes, it does make for a more
reliable machine, theoretically. We have 5 DN2500's and about a dozen
Sparcstations in our department with at least 8 or 16 MB each, of which
roughly 50% is 3rd party RAM. They've been running for nearly a year
with 0 failures. I can live with that kind of error rate. As for the
form factor ... with 4 MB SIMMS now running about $75/MB in the PC
market I can stuff 64 MB inside my DN2500 for about the same cost of
buying a single 8MB add-on for a HP 9000. If space is really critical,
then look at what Sun did for the Sparc SLC -- they went with another
PC SIMM design which use 1Mx4 chips rather than 4Mx1 chips, and got
a 4MB SIMM with a 32-bit data path on a single card. This is apparently
a PC SIMM which was already on the price list of the company that we
order our 1MBx9 SIMMS from some 6 months prior to the announcement
of the Sparc SLC.

The fact is that the HP market is so much smaller than the PC market,
that any HP designed memory, 3rd party or not, will cost 4 to 5 times
what the same capacity will cost in the PC market. Period.


 -- David Krowitz

krowitz@richter.mit.edu   (18.83.0.109)
krowitz%richter.mit.edu@eddie.mit.edu
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