Testing annual glare simulation on a server with 16 CPUs

I need to run annual glare simulations for 200 views, so I decided to create a large amazon server with 16 CPUs. I entered 16 in the number of CPUs input in the daylighting simulation component and I ran the simulation. I opened the server's resource moniter and found out that rcpict is using only 6 CPUs. Am I missing something? Do I need to change anything else in the daylighting simulation component to make Radiance use all 16 CPUs.

Thanks