Håkon Bugge wrote: > At 21:00 17.11.2007, Chris Samuel <[EMAIL PROTECTED]> wrote: >> I should also point out that we're using the PGI 7.x series of >> compilers and tell our users to build with: >> >> -tp k8-64,barcelona-64 >> >> so that they get the optimisations for both dual and quad core chips >> (with the appropriate path selected at run time). > > While I did the SPEC MPI 2007 for the Barcelona, I got the following > projections (8 nodes, 8 cores per node) for SPECmpiM_base2007: > * PathScale 3.0, -march=core: 5.53 > * PathScale 3.0, -march=opteron -msse3: 5.32 > * PGI 7.0-7, -tp barcelona-64 + lots of fancy switches: 4.71 > * PGI 7.0-7, -tp barcelona-64 -nomovnt -fast: 4.75 > I didn't have much time to play with compiler options. It was > interesting to see that the "wrong" architecture was better using the > PathScale compiler. Further, PathScale was significant better than PGI > 7.0-7, even though PGI had support for the "right" architecture. > > The switches used for the PathScale compiler can be found at the SPEC > web, http://www.spec.org/mpi2007/results/res2007q4/ > > The final rate (5.61) was better, due improved memory bandwidth (due to > a better BIOS).
No big secret, I don't think. Core optimized code will be scheduled for a wider SIMD unit, same as Barcelona. -- Geoffrey D. Jacobs To have no errors would be life without meaning No struggle, no joy _______________________________________________ Beowulf mailing list, Beowulf@beowulf.org To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
