Slave licenses have nothing to do with cores, in principle.
Slave licenses are used by ATK to submit multiple MPI processes. Having N slave licenses allows you to run an calculation parallelized over N+1 (the master is also used) processes, using a command like "mpiexec -n N+1". If you choose to run all these processes on the same computer (using the cores as processors), or on different computers, is up to you, and is not dependent on the licenses you have.
If you submit the N+1 processors on different machines, ATK can additionally thread over the cores, but you don't need any extra licenses for that. This offers the best performance possible with ATK; running more MPI processes than sockets on the same machine is not advisable.
In the future ATK will become memory-parallel, and that will change the picture a bit, and make running multiple MPI processes on the same computer more efficient.
