I'm doing some benchmarking on a dual 1.8GHz Opteron system with 4GB of RAM running SuSE 8.2 Pro BETA 9 - and mostly it looks nice, except for the occasional strange hickups. For example, I compiled the standard LINPACK Fortran benchmark program. If I run the same program twice in a row then I sometimes see a *long* delay in running time. A run with "time" shows that the delay is not in "user" time but in system: [1] opteria:~/src/linpack> time out/opteria/linpack.g77 ... xtimes are reported for matrices of order 1000 factor solve total mflops unit ratio times for array with leading dimension of1001 2.450E+00 0.000E+00 2.450E+00 2.729E+02 7.328E-03 4.375E+01 end of tests -- this version dated 10/12/92 2.520u 0.020s 0:02.53 100.3% 0+0k 0+0io 158pf+0w ---> Ca 273 MFLOPS. [0] opteria:~/src/linpack> time out/opteria/linpack.g77 Please send the results of this run to: ... xtimes are reported for matrices of order 1000 factor solve total mflops unit ratio times for array with leading dimension of1001 2.697E+01 8.000E-02 2.705E+01 2.472E+01 8.091E-02 4.830E+02 end of tests -- this version dated 10/12/92 2.680u 25.370s 0:28.04 100.0% 0+0k 0+0io 158pf+0w ---> Ca 25 MFLOPS, and a whopping 25.37 seconds spent in system-space. Any suggestions as to why I'm seeing these delays? The machine is more or less idling... [0] opteria:~/src/linpack> uname -a Linux opteria 2.4.21-60-smp #1 SMP Tue Sep 2 11:34:54 UTC 2003 x86_64 unknown unknown GNU/Linux I've tried the NUMA kernel, but it doesn't make any difference. -- Peter Eriksson <peter@ifm.liu.se> Phone: +46 13 28 2786 Computer Systems Manager/BOFH Cell/GSM: +46 705 18 2786 Physics Department, Linköping University Room: Building F, F203 SE-581 83 Linköping, Sweden http://www.ifm.liu.se/~peter