Subject: Re: AMD 586 dx4 133 support
To: Chu Chiu Leung <>
From: Michael L. VanLoon -- <>
List: port-i386
Date: 09/10/1996 22:48:55
>to add to the AMD Am5x86-P75 discussion,
>it's running at 40MHz external clock, with
>a DHRYSTONE result of 140,000 dhrystones/second.
>BIOS(old!) detect a 150MHz CPU.

Yes, it will benchmark very impressively.  Especially if the benchmark
fits in cache.

Where you will see things slow down a lot closer to normal 486 levels
is when you start hitting the bus and DRAM.  You're *really* getting
close to total bus saturation when running 4x on a 33-40MHz bus
(vs. 60-66MHz on a Pentium), where you don't have advanced things like
pipeline burst cache, etc.

A better test is to run something big that hits the drive
occasionally.  Like timing a kernel build.

Anyway, for comparison.  There are many different versions of
dhrystone out there.  My 5x86 133MHz dhrystones at ~87,000
dhrystones/sec., on the version I built.  My 486DX2 80MHz ~75,000.  My
Pentium 120MHz ~176,000.

A better test is a make world.  My P120 does it about 2-2.5 times
faster than my 5x86 133MHz did.

  Michael L. VanLoon                 
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