Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!uunet!crdgw1!sixhub!davidsen
From: davidsen@sixhub.UUCP (Wm E. Davidsen Jr)
Newsgroups: comp.sys.ibm.pc
Subject: Re: 386 Memory question (simms)
Message-ID: <1072@sixhub.UUCP>
Date: 4 Jun 90 02:28:18 GMT
References: <5923@buengc.BU.EDU>
Reply-To: davidsen@sixhub.UUCP (bill davidsen)
Distribution: usa
Organization: *IX Public Access UNIX, Schenectady NY
Lines: 35

In article <5923@buengc.BU.EDU> rem@buengc.bu.edu (Robert E. Mee) writes:
| I have a question about memory configurations
| for a 386 system. I'm about to buy an SX that
| comes standard with 1mb in 4 256k simms. I asked
| the salesperson if it was possible to have 1
| 1mb simm in it's place. He went on to say that 
| in order to use 1mb simms I have to use a minimum
| config of 4 meg!!!

  The answer is "probably not." For an SX you must add memory in at
least 16 bit increments, so with simms you need at least two. In a DX
you need at least four. The "at least" comes from the possibility of
interleaved memory which them requires multiples of four for SX, eight
for DX.

  I don't believe that Arche has interleave, but if it does the saleman
is correct.

  I will note that some systems can be run either way, and there was a
big stink about Tandy when their 386 first came out. Some magazines got
better performance than others and people claimed that Tandy had
supplied special models for testing. What actually did happen is that
Tandy supplied versions with 2MB, and the system ran interleaved. The
testers who only used 1MB didn't have interleave and the system ran 20%
slower due to wait states.

  The moral of this is that even if you can add just 2 simms, if your
system has interleave you probably want to take advantage of it! An SX
isn't a lot faster than an AT to start with, and adding wait states is a
good way to bog it down.
-- 
bill davidsen - davidsen@sixhub.uucp (uunet!crdgw1!sixhub!davidsen)
    sysop *IX BBS and Public Access UNIX
    moderator of comp.binaries.ibm.pc and 80386 mailing list
"Stupidity, like virtue, is its own reward" -me