Not sure I am using correct terms/language to describe the problem, but I will try.

I want to run several Julia processes on one PC (Monte Carlo simulations). When I do it in Matlab, I simply start several Labs, and the loss in the speed of computation in moving from running one lab to 8 labs is about 30% (approximately, naked eye, based on some tick toks but not two markov chains are identical in speed)

When I do the same with Julia, the loss in speed from moving 1 to 8 engines is more substantial, I would say 60% or more, wiping out nearly the whole gain in moving from Matlab to Julia.

I am not using any fancy external dependencies, very simple code, using Julia 1.2 + several packages like Random, DelimitedFiles etc.

So the question is: may be there are some setting (in Atom?), language features (?) etc which will reduce this loss?

If relevant, it is AMD 3950x.

PS. yes, there is a similar thread, Slow down when running several parallel julia processes which use BLAS (MWE is provided) but I understand very little there, not sure I have the same reason, as I know nothing of BLAS.gemv! mentioned there.