Re: Problems with too much memory (?)

Aaron M. Ucko (
22 Apr 1997 20:26:55 -0400

Pavel Machek <> writes:

> This still may be hw problem, but aybe it is not.
> My machine is 486DX2/80, 128kb level 2 cache (stolen from one 386 :-),
> 20MB ram (16M+4M). It compiles kernel about 32 minutes.
> When I removed 4MB SIMM, compilation time went down to 22 minutes. I
> thought that it is hardware problem, but I wanted to investigate it more.
> So I put memory back and limited memory to 16M (mem=16M). Compile time
> stayed at about 22 minutes.
> So I suspect linux tfor having problems with too much memory.

The problem is more likely that your motherboard can only cache 16M of
your memory, so accessing the top 4M is significantly slower than
accessing the lower 16M, causing a performance decrease in many
cases. Increasing the amount of your L2 cache and/or changing your
BIOS settings may fix this.

Aaron M. Ucko ( | For Geek Code, PGP public key, and other info,
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