Ray works well with Intel Hyper Threading (HT) Technology.

If the cluster nodes have HT enabled (in bios and in the operating system), then
you can schedule Ray on all the logical cores.

== Example ==

A Xeon Nehalem <something> has 4 physical cores.
Each core has two threads visible by the operating system, but both utilise the
same space on the chip.

If you have 5 computers and each has 2 Xeon Nehalem <something> processors,
then each computer has 8 physical cores and 16 logical cores.

Basically, you can start Ray with 5*16 MPI ranks instead of 5*8 MPI ranks.

== Default value ==

By default, almost all clusters have the HT disabled in the bios.


