Christoph Hormann wrote:
> gRRosminet wrote:
> 
>>
>> I have downloaded the official binary for linux and ran the benchmark.
>>
>> Official : 45 minutes 08 seconds ( 2708 seconds )
>> gcc pentium4 optimized : 36 minutes 43 seconds ( 2203 seconds )
>> ICC pentium4 optimized : 33 minutes 01 seconds ( 1981 seconds )
>>
>> ratios (official / optimized) :
>> Official : 1
>> gcc pentium4 optimized : 1.229
>> icc pentium4 optimized : 1.367
> 
> 
> My test results look quite different:
> 
> official 3.5:              2394s
> 3.6 RC1 (gcc 3.4):         2292s
> 3.6, optimized* (gcc 3.4): 2274s
> 
> *) -march=athlon-xp -mfpmath=sse -mmmx -msse -m3dnow
> 
> And before someone asks: profiling based optimization also does not 
> change much about this (i tested this some time ago).
> 
> The most likely explanation for your results to me seems the pentium 4 
> being particularly bad at running code not specifically optimized for 
> its design.
> 
> Christoph
> 



Could you try it with an optimized version of 3.5 ?
The first time I tried to compile an optimized version of povray, it was 
on an Athlon Thunderbird and I get very good results on a personal scene 
(wich didn't use so many functionnalities as the benchmark one)


for my pentium 4, an other explanation could be that the sse2 
instruction are really better on floating point than sse.
In your case, you limit yourself at using SSE instruction whereas Athlon 
processors have an excelent fpu unit. you should replace -mfpmath=sse by 
-mfpmath=sse,387

Here is the GCC man page about this option :
sse,387

Cela double effectivement le nombre de registres disponibles et




Thierry


P.S. : please don't tell me that P4 is a bad processor : I know it but I 
don't want to hear about it ! ;-P

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