On Monday, February 2, 2015 at 4:20:30 PM UTC-8, Seth wrote: > > > > On Monday, February 2, 2015 at 12:05:45 PM UTC-8, Peter Simon wrote: >> >> Do 0.3 and 0.4 use the same number of threads by default? You could try >> calling blas_set_num_threads prior to peakflops to make sure. I get best >> results when the number of threads is equal to (or slightly less than, for >> 12 cores) the number of physical cores. >> >> --Peter >> >> > Doesn't seem to make much difference. > > Julia 0.3.4: > > julia> blas_set_num_threads(4) > > > julia> peakflops() > 9.094162579243195e10 > > Julia 0.4: > > julia> blas_set_num_threads(4) > > > julia> peakflops() > 1.6471473036802423e9 >
Problem identified: when I check activity monitor, it appears that it's a single thread in 0.4.0 (I'm getting CPU utilization of 98% when it's running), whereas in 0.3.4 it appears to be using all 4 threads (CPU utilization of 396%). This is even after blas_set_num_threads(4), so I'll file an issue. Thanks!
