multicore AMSD run

Hi 

I would like to know if the following is  do able . 

Cadence version : IC 6.1.8

I am running a top level AMSD run with spectre X and xcelium for the digital . I have acess to an 8 core machine. Is it possible in a top level run to be able to specify the no of cores for spectre X and xcelium  separately. For eg can I  run spectre x on 6 cores and xcelium on 2 cores in one single AMSD run . Any pointers to a RAK or other documentation would be helpful 

Thanks