> Default allocator settings can call malloc/mmap a lot, and is sensitive to latency on those calls. Under host memory bandwidth pressure, BEAM can grind to a halt. Tuning BEAM's allocator settings is imperative to avoid this. Namely, MHlmbcs, MHsbct, MHsmbcs and MMscs. This was especially noticeable after meltdown was patched.

Excessive allocations and memory bandwidth are two very different things. Often then don't overlap, because to max out memory bandwidth you have to write a fairly optimized program.

Also, are the allocations because of BEAM or is it because what you are running allocates a lot of memory?