> Silly me... > > I was using python anaconda and it seems to be user more than one process...
No, OpenBLAS used by Julia should also use several threads. You can change the number of threads like so: ~/julia/tmp >> export OPENBLAS_NUM_THREADS=2 ~/julia/tmp >> julia5 tt.jl I actually get the best results for one thread, at leas for you matrix size you use.
