Hello to all,
I have a big doubt about the target-cpus. On my server, as native target-cpu is selected "Cannonlake". I made a sweep among all the possible target-cpus, and to my surprise the target-cpu "knl" was the one that gave me the best performance. This doesn't make much sense, so I want to ask you what could have happened?
The program is the n-body algorithm, I do mathematical calculations that are not very rare.
Obviously I always compile with --release and opt-3.
Any help to understand this ? If I change the server I will have to run with all the target-cpu and keep the best one, does it make sense to do so ?