1ba045f4_he_GATK___RETIRED___GATK_Forum__Shared_Memory
[Property] Scalability [Scatter/Gather] Hundreds of processes. Limited by capabilities of the underlying storage system, in general. Isilon-class storage can run thousands of jobs effectively. [Shared Memory] 
Fewer than 32 cores. Each thread operates completely independently, so N threads requires N times more memory than 1 thread alone. Best scaling at 8 or fewer threads.
Parallelism with the GATK - RETIRED - GATK-Forum
Shared Memory