Hi! On Tue, Aug 31, 2010 at 8:11 AM, Yeb Havinga <yebhavinga@xxxxxxxxx> 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. -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
