In this chapter, some of the POWER processors are briefly mentioned as examples, in order to show the development stages of the POWER architecture. However, it is not the aim to provide a complete description of all POWER generations. You can find a lot of good literature on the subject on the Internet.

Up to and including the POWER3 processor, all POWER processors had only one data processing logic unit (from today’s perspective 1 processor core). With the POWER4 processor, the first POWER processor with 2 processor cores appeared in 2001. With the introduction of the POWER5 processors in 2004, SMT was available for the first time. The number of processor cores on a processor was continuously increased with the next generations of POWER processors to up to 24 processor cores for POWER9 processors. At the same time, the number of SMT threads was increased from originally 2 for POWER4 processors to up to 8 SMT threads for POWER8 and POWER9.

The new POWER10 generation will support up to 30 processor cores. The first systems are to be delivered in 2021.