I just noticed that the following line
julia -e 'using Pkg; Pkg.add("BenchmarkTools"); using BenchmarkTools; N = 1000; A = rand(N, N); B = rand(N, N); @btime $A*$B'
gives around 530 ms in my laptop when using guix provided julia. Same
behavior when running within a guix container.
This very same code, using the binary one may download from the julia
site gives 15 ms.
I’m using here an up to date guix. As a reference, julia binary
provided by archlinux takes also 15 ms.