Enhanced SMT Controls for POWER7

Simultaneous Multi-Threading (SMT) allows sharing of processor facilities to run two or more threads of execution at the same time on a single processing core. On POWER7, each processing core supports up to 4 threads of execution. SMT generally increases the performance capacity of a system and can improve the responsiveness of multithreaded applications. Running multiple instruction streams at the same time does not, however, improve the performance of any given task. POWER8 and POWER9 support up to 8 threads per processor core.