On Thu, 25 Aug 2005, Stephen Rankin wrote:
>> Is this actually telling us that the PowerPC memory bandwidth is poor? Or
>> that gcc 3.x is ill-optimised for it. I'm hopeless at interpreting
>> benchmarks.
my tests are with gcc-4 at the moment. I'll replay with gcc-3.3
> Here are the G5 1.8GHz PPC idle results:
>
> no opt 1m3.805s
> -O2 0m44.355s
> -O3 0m44.393s
> -O3 -faltivec 0m44.349s
> -O3 -faltivec -mcpu=powerpc64 0m17.346s
>
So your last benchmark is faster than my equivalent one on 2.7GHz...
Crazy.
--
Tim Jenness
JAC software
http://www.jach.hawaii.edu/~timj
|