I would like to know how the binaries on the Julia downloads page page are generated. For example, what are the default compilation flags used? Would I get the same result if I compiled them on some (Linux) system, assuming I do not link to any system libraries?
I ask because I am going to be running Julia on a cluster and I am concerned I may not be taking full advantage of the compute node architecture.
As an example, diagonalising a 4096 by 4096 Hermitian matrix using
eigen! takes around 22-23 seconds on my computer (with 8 threads), but 15-16 seconds on a node of a cluster (which has 40 threads). I don’t expect a 5x speedup, but how do I ensure that the LAPACK that is being called really does know about 40 threads being present (and using them all)?