POV-Ray : Newsgroups : povray.unix : Performance Confusion with AMD Opteron 880 : Re: Performance Confusion with AMD Opteron 880 Server Time
2 Jun 2024 23:09:18 EDT (-0400)
  Re: Performance Confusion with AMD Opteron 880  
From: Nicolas Calimet
Date: 10 Nov 2006 16:50:57
Message: <4554f441@news.povray.org>
> Rendered at 800x600 with no AA
> the example below gives times of 7 sec on the Opteron and 2 sec on the
> laptop.

	OK, I can confirm this slowdown with a binary prepared using gcc-4.1.1
in 64-bit mode (comparisons made with 32-bit povray on k7 and p4 machines).

	This looks like a gcc problem when generating 64-bit code, as I can get
expected render times using the same compiler optimizations AND the -m32 gcc
flag to produce a 32-bit binary.  Furthermore, it's likely this problem exists
only in the gcc-4.1.x series, since older versions (namely 3.4.2, 3.4.3, 4.0.0)
produce 64-bit binaries rendering at the expected speed.  But that needs more
investigation before one files a bug report to the gcc devs.

	- NC


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