[rocket_science]

So finally against Ansys tech recomendations I found that the fastest and most stable settings both for Fluent and CFX is:

1. No need to tune anything in BIOS. Just leave default E cores and HT turned on.

2. Run a case on all cores (P+E) with HT.

Let's say, if you have i9-13900 with 32 threads (HTed 8xP + 16xE) - run a case partitioned to 32.


My main concern was not speed up but accidental fatal errors during calculations - now everything is OK.
However you can try to run a case partitioned to P cores number only - it would simulate ok but a little slower. Just don't turn off E cores or HT in BIOS.

PS. This is relevant for Win11 23H2 and tested on two different PCs with i12 CPUs both on intel mpi and ms mpi.