Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!usc!zaphod.mps.ohio-state.edu!rpi!sci.ccny.cuny.edu!sukenick
From: sukenick@sci.ccny.cuny.edu (SYG)
Newsgroups: comp.sys.mac.hardware
Subject: Re: Memory speeds can be critical (was: SIMMs for IIsi - what do I need?)
Message-ID: <1990Dec24.190451.21995@sci.ccny.cuny.edu>
Date: 24 Dec 90 19:04:51 GMT
References: <2924@ux.acs.umn.edu> <NCrwEGxa@visix.com> <2946@ux.acs.umn.edu> <NCMjwy7m@visix.com>
Organization: City College of New York - Science Computing Facility
Lines: 16

>memory support logic that has been designed to handle different speeds
>of memory has to be explicitly configured (via jumpers or something

>just that this "same-speed" claim contradicts both my own experience
>and my understanding of dynamic RAM technology, which so far has

Same with me.  The other arguments for "same speed only" so far haven't
convinced me.  Can anyone come up with a convincing mechanism as to why
mixed speed memory will not work?  The memory speed only refers to time
between select (or whatever signal) and when data is ready to be input
or output.

The only possible problem I could see with higher speed memory is their
faster rise time which may introduce noise (or ring) for a board not designed
for them......   But the speed difference is relatively small, so I would
not think that this is a factor.