Hi!
On Tue, Aug 31, 2010 at 8:11 AM, Yeb Havinga <yebhavinga@gmail.com> wrote:
> 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
Ok, this could explain the huge difference. I was planing on getting
GigaByte GA-890GPA-UD3H, with a Phenom II X6 and that ram: Crucial
CT2KIT25664BA1339, Crucial BL2KIT25664FN1608, or something better I
find when I get enough money (depending on my budget at the moment).
> MB: 790FX chipset (Asus m4a78-e)
>
> regards,
> Yeb Havinga
>
>
Thanks for the extra info!
Ildefonso.
