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From: hdrw@ibmpcug.co.uk (Howard Winter)
Newsgroups: comp.sys.ibm.pc.hardware,comp.sys.ibm.pc.misc,connect.audit
Subject: Re: Memory Too FAST?!?!?!
Message-ID: <1991Jun25.224640.4601@ibmpcug.co.uk>
Date: 25 Jun 91 22:46:40 GMT
Organization: The IBM PC User Group, UK.
Lines: 30

[about whether DRAM chips with a faster speed rating than needed should work]
You are right, he is wrong - the speed rating is related to the time the chip
needs for its output data to stabilise after the 'Read' signal is asserted
(for the purists - this is s Gross Simplification).  Having chips
that are too fast just means they sit around with valid data for
longer - They should work perfectly.
The only other parameter which could affect things is how often they
need to be refreshed, and I can't imagine that's going to be a problem -
the refresh allowance is normally very generous - otherwise unreliable
memory would result.  Also this doesn't sound like your problem.
Power requirement normally goes up with faster chips, but unless the PSU
is almost at its limit in the original setup, that's unlikely to be it
either.
BUT there are two modes of accessing SIMMs - and this is where I can't
remember the details, but I think its page mode and interleave mode.
Not all DRAMs can do both, I think, so it could be yours are being
driven by the Dell in a mode they aren't designed to use.
Someone else can probably fill in the details of this - sorry I
can't do so.

Good luck
Howard.


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-- 
hdrw@ibmpcug.Co.UK     Howard Winter     0W21'  51N43'