Can Dengine.affinity=0 setting improve data function performance in Tibco Spotfire Statistics Services?

In Tibco Spotfire Statistics Services, each data function is using its own TERR engine instance, which in turn can be tied to a single CPU core by setting -Dengine.affinity option. In some cases, data function performance with -Dengine.affinity=0 might, indeed, be better than setting -Dengine.affinity=1-9999. Using 0 value will specify all CPUs ("disable assigning engine affinity") and can result in a higher level of multiprocessing.

-Dengine.affinity=1-9999 would assign a specific CPU to each engine process, but would round-robin through the CPUs.

-Dengine.affinity=0 doesn't do anything to tell the operating system how to allocate CPUs to engines.

Engine affinity was originally put in place in a different era of CPU management, before multi-core processors were commonplace. Given how more modern Windows servers usually use multiple CPU cores, it might no longer be necessary. Engine affinity was also put in place at a time when R was almost exclusively single-threaded, and had no capability for multi-core processing. Today, TERR uses Intel's Math Kernel Library internally to do multi-core parallelism on some complex calculations, thus, performance could improve in some cases by setting -Dengine.affinity=0.

Reference: Dengine.affinity=0 setting in Tibco Spotfire Statistics Services