Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ames!amdahl!key!russ
From: russ@key.COM (Russell Donnan)
Newsgroups: comp.sys.mac.hardware
Subject: Re: Is OK to mix 120ns with 70ns on IIC
Keywords: AARgh!
Message-ID: <1448@key.COM>
Date: 13 Feb 90 19:20:56 GMT
References: <656@tci.bell-atl.com> <88500005@uxh.cso.uiuc.edu> <13800@phoenix.Princeton.EDU>
Reply-To: russ@xanadu.key.COM (Russell Donnan)
Organization: Key Computer Laboratories, Fremont
Lines: 40

In article <13800@phoenix.Princeton.EDU> MARCELO@phoenix.princeton.edu (MARCELO) writes:
{In article <88500005@uxh.cso.uiuc.edu> johnsone@uxh.cso.uiuc.edu writes:
{> The people at some of the MacMailOrder places have told me that the speed
{> doesn't matter, but the dealer here in town said that it might -- as a

A DEALER told you this???  You have to be kidding!

{> 
{> So what's the correct answer?  Does it make a difference?
{> 
{>                                      Erik A. Johnson
{
{     When working for an Apple dealer I found that memory hogs (like 
{HyperCard) tend to have problems with simms of different speeds .. I even 
{had some Macs come in with the "Sad Mac" bootups and when running diags on 
{them the problem turned out to be the simms (different speeds) .. Although 
{I'm not sure if the simms went bad because of faulty manufacturing or 
{becasue of the mix of speeds but to stay on the safe side I would recomend 
{keeping the speed the same ..

I was forwarded a thread from rec.audio where people where painting
their CD collection green because it made the audio sound better.
If this isn't funny, read on:  ;-)
Lets get one thing straight:  The Mac (excluding the IIci) is going
to expect to be able to get data from the RAMs in 120ns.  The speed
quoted on your SIMMs is the worst case data access of the RAMs.  Now what
that means to you and me is that ANY RAM chips which will have the
data available to the Mac by 120ns will work.  Putting faster RAMs
in won't help you, but it won't hurt you either.  Your only real
constraint is, that you must put the same SIZE SIMMs in the same RAM
bank.  Its getting pretty damn hard to find 120ns SIMMs these days,
but if you can, they are cheaper.

Cheers!
-Russ
-- 
Russ Donnan  (415) 623-2121
Amdahl Corporation, Key Computer Laboratories, Fremont, CA, USA
russ@key.amdahl.com, ...!{pacbell,sgi,amdahl}!key!russ
-To capture the essence of an opinion takes but one lawyer.