Re: Different speed SIMMs causing slow down

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#20628

From: Zhahai Stewart
Date: Mon, 11 Apr 1994 11:07

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boonlow@kits.sfu.ca (Boon Chong Benjamin Low) wrote:
> He upgraded from 16mb to 32 mb and the system doesn't seem any faster,
> he's running memory intensive compilations under Linux.
> His first 16mb is 70ns and the other 16mb is 80ns.
> Could that pose a problem ??
> 
> Also, he has only 64kb of internal cache on the motherboard, would
> upgrading to 256kb helps ?

It might.  Some motherboards direct map the cache to a particular memory
area - like the first 64K only caches the first 8/16 MB of main memory, so
an additional 8/16MB runs uncached and slow.  I've heard of other cases 
where more memory runs slower for that reason.

Also, for lesser effect, just 64K of cache is fairly small for 32 MB of memory,
so your hit rate might go down some; this shouldn't be dramatic, tho.
    Z
zstewart@nyc.cs.du.edu

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From: zstewart@nyx10.cs.du.edu (Zhahai Stewart)
Subject: Re: Different speed SIMMs causing slow down
Message-ID: <1994Apr11.110710.1264@mnemosyne.cs.du.edu>
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Date: Mon, 11 Apr 94 11:07:10 GMT
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