[Beowulf] slightly [OT] smp boxes

Patrick Geoffray patrick at myri.com
Mon Oct 20 02:36:21 PDT 2008

Greg Lindahl wrote:
> Submit one. HPCC isn't perfect, but it's the best that's available,

I disagree. The tests integration sucks and some of the tests themselves 
are poorly written. For example, last time I looked, bench_lat_bw 
measures *8* half-RTTs with MPI_Wtime(). If your MPI_Wtime() is not 
using cycle counting instructions by default (which is not portable), 
then you are screwed.

Getting the timing right is benchmarking 101.


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