root@blackbird:~ # ./stream_bench 838860800 512 `seq 0 4 31 ` Using OS page size of 4KB Array size multiple (elements) = 512 Per-CPU work size (elements) = 104857600 ------------------------------------------------------------- STREAM version $Revision: 5.10 $ ------------------------------------------------------------- This system uses 8 bytes per array element. ------------------------------------------------------------- Array size = 838860800 (elements), Offset = 512 (elements) Memory per array = 6400.0 MiB (= 6.2 GiB). Total memory required = 19200.0 MiB (= 18.8 GiB). Each kernel will be executed 10 times. The *best* time for each kernel (excluding the first iteration) will be used to compute the reported bandwidth. ------------------------------------------------------------- Number of Threads requested = 8 Number of Threads counted = 8 ------------------------------------------------------------- Your clock granularity/precision appears to be 3 microseconds. Each test below will take on the order of 425143 microseconds. (= 141714 clock ticks) Increase the size of the arrays if this shows that you are not getting at least 20 clock ticks per test. ------------------------------------------------------------- WARNING -- The above is only a rough guideline. For best results, please be sure you know the precision of your system timer. ------------------------------------------------------------- Function Best Rate MB/s Avg time Min time Max time Copy: 21849.3 0.614596 0.614288 0.615881 Scale: 21832.0 0.615070 0.614775 0.615456 Add: 24267.2 0.829715 0.829624 0.829784 Triad: 24732.1 0.814352 0.814029 0.814623 ------------------------------------------------------------- Failed Validation on array a[], AvgRelAbsErr > epsilon (1.000000e-13) Expected Value: 1.153301e+12, AvgAbsErr: 1.106056e+12, AvgRelAbsErr: 9.590353e-01 For array a[], 838860800 errors were found. Failed Validation on array b[], AvgRelAbsErr > epsilon (1.000000e-13) Expected Value: 2.306602e+11, AvgAbsErr: 2.209965e+11, AvgRelAbsErr: 9.581043e-01 AvgRelAbsErr > Epsilon (1.000000e-13) For array b[], 838860800 errors were found. Failed Validation on array c[], AvgRelAbsErr > epsilon (1.000000e-13) Expected Value: 3.075469e+11, AvgAbsErr: 2.946620e+11, AvgRelAbsErr: 9.581043e-01 AvgRelAbsErr > Epsilon (1.000000e-13) For array c[], 838860800 errors were found. ------------------------------------------------------------- root@blackbird:~ # uname -a FreeBSD blackbird.east.rtk0.net 13.0-CURRENT FreeBSD 13.0-CURRENT r348447 GENERIC powerpc