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