Re: Incredible!


Subject: Re: Incredible!
From: Timothy A. Seufert (tas@mindspring.com)
Date: Tue Sep 18 2001 - 14:08:21 MDT


At 7:47 AM -0400 9/18/01, cbsled@ncia.net wrote:
>On 09/12/01, at 04:18 PM, Robert Brandtjen <rob@prometheusmedia.com> said:
>
>>Most such tests in the past shown the mac to be in fact slower.
>
>Here's another anecdotal data point.
>Using the GRASS GIS program <http://www.baylor.edu/~grass/index2.html> under
>RH 6.2 on a AMDK6-2 400 and under Linuxppc 2000 on a G3-300 Powerbook, a
>very large floating point number crunch, which would have taken over six
>days to complete on the PC, ran in just under 23 hours on the Powerbook.
>The program was compiled from the same source code on both machines.

This is not surprising: the entire K6 series is known for *very* poor
x87 floating point performance. The only way to get decent FP
performance out of a K6-2 or K6-3 is to use 3DNow! (AMD's own SIMD
extension for the x86), which requires hand coded assembly language
as most compilers do not automatically emit 3DNow! instructions.

-- 
Tim Seufert



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