Re: Performance on new 64bit server compared to my 32bit desktop

Greg Smith wrote:
> Yeb Havinga wrote:
>> model name : AMD Phenom(tm) II X4 940 Processor @ 3.00GHz
>> cpu cores : 4
>> stream compiled with -O3
>> Function Rate (MB/s) Avg time Min time Max time
>> Triad: 5395.1815 0.0089 0.0089 0.0089
> I'm not sure if Yeb's stream was compiled to use MPI correctly though,
> because I'm not seeing "Number of Threads" in his results. Here's
> what works for me:
>
> gcc -O3 -fopenmp stream.c -o stream
>
> And then you can set:
>
> export OMP_NUM_THREADS=4
Then I get the following. The rather wierd dip at 5 threads is
consistent over multiple tries:

Number of Threads requested = 1
Function Rate (MB/s) Avg time Min time Max time
Triad: 5378.7495 0.0089 0.0089 0.0090

Number of Threads requested = 2
Function Rate (MB/s) Avg time Min time Max time
Triad: 6596.1140 0.0073 0.0073 0.0073

Number of Threads requested = 3
Function Rate (MB/s) Avg time Min time Max time
Triad: 7033.9806 0.0069 0.0068 0.0069

Number of Threads requested = 4
Function Rate (MB/s) Avg time Min time Max time
Triad: 7007.2950 0.0069 0.0069 0.0069

Number of Threads requested = 5
Function Rate (MB/s) Avg time Min time Max time
Triad: 6553.8133 0.0074 0.0073 0.0074

Number of Threads requested = 6
Function Rate (MB/s) Avg time Min time Max time
Triad: 6803.6427 0.0071 0.0071 0.0071

Number of Threads requested = 7
Function Rate (MB/s) Avg time Min time Max time
Triad: 6895.6909 0.0070 0.0070 0.0071

Number of Threads requested = 8
Function Rate (MB/s) Avg time Min time Max time
Triad: 6931.3018 0.0069 0.0069 0.0070

Other info: DDR2 800MHz ECC memory
MB: 790FX chipset (Asus m4a78-e)

regards,
Yeb Havinga