Bill Studenmund wrote:
> 
> > I've successfully mixed 80ns with 70ns in the same bank.  I believe it's
> > fine as long as you make sure that they are all fast enough.  It's a bit
> > of a waste, tho, since you won't see that 10ns speedup if you do mix them.
> 
> What speedup? True 70 ns chips are faster than 80 ns, but I was trying
> to get at the fact that the Mac doesn't change its memory timing (at least
> in these computers), so the CPU will take as long to access 70 ns memory as
> 80 ns memory. So a full bank of 70 ns will be accessed as fast as a full
> bank of 80 ns RAM, which is as fast as a mixed bank.

Really?  I didn't realize that.  I'd thought that it could actually
access faster memory faster, but I guess that implies some kind of
dynamic memory bus speed detection that just doesn't exist on Macs.  Oh
well, you live and learn :-)

> I agree with Paul about what happens if one of the SIMMs is NOT
> fast enough for the machine. :-)

Definitely, interesting hangs and crashes if I remember correctly.

> Also, since we started talking about IIsi's, don't forget that that bank
> of memory will be accessed as fast as a 100 ns chip! :-)

Is it that slow?  Ouch.

Thanks for the info!

-- 
Colin Wood                                 cwood@ichips.intel.com
Component Design Engineer - MD6                 Intel Corporation
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I speak only on my own behalf, not for my employer.