The HPDS2 Procedure

The PERFORMANCE statement defines performance parameters for multithreaded and distributed computing, passes variables that describe the distributed computing environment, and requests detailed results about the performance characteristics of PROC HPDS2.

You can also use the PERFORMANCE statement to control whether PROC HPDS2 executes in single-machine or distributed mode.

It is important to remember the distinction between the NODES= and NTHREADS= options. The NODES= option specifies the number of separate distributed nodes that participate in the DS2 execution, whereas the NTHREADS= option determines how many independent copies of the DS2 program are run in parallel on each node. If the data are located on the grid, then all nodes must be engaged; therefore, the NODES= option might be overridden. Setting NODES=0 causes the DS2 code to execute on the client side only. Setting the NTHREADS= option to a value that is greater than the CPU count on each grid node is not likely to improve overall throughput.

For more information about the PERFORMANCE statement, see the section PERFORMANCE Statement of Chapter 2: Shared Concepts and Topics.