How to speed up multi-model optimization?

Hi all,

Normally, I use '-mmo -mpi i -np9' for multi-model optimization. and assign np=3 each for model 1 and model 2.

in order to speed it up, I added '-nt 4 -mmo -mpi i -np9' it works. but when i want to use more cores, Altair optistruct just stop working and exit..

what is correlation between -nt and -np?

Thanks,

D