Hi,

I am new to Julia Language and I am curious to use it for my work. 
Recently, I have tried to use it for some of my projects and observed some 
interesting cases.

First of all, when I start Julia REPL without adding any worker processes 
and do matrix multiplication. Julia takes all CPU cores in my computer to 
speed up the computation. I guess it used OpenBLAS. The code is
X = randn(5000, 5000); Y = randn(5000, 5000); X * Y;


However, after adding some worker processes by using *addprocs*(4) and do 
matrix multiplication. It runs the computation on only 1 CPU core and it 
slows down my performance. Even if I remove all worker processes that I add 
and run the multiplication again, it still uses one CPU core to do. The 
code is
addprocs(4); X = randn(5000, 5000); Y = randn(5000, 5000); X * Y;
rmprocs(2); rmprocs(3); rmprocs(4);rmprocs(5);X = randn(5000, 5000); Y = 
randn(5000, 5000); X * Y;


My question here is that: Are there any ways to use all cores to do matrix 
multiplication ( and other matrix methods) with multiple cores after 
*addprocs*()?

Thanks.

Reply via email to