2.1.5 Power10 compatibility modes
The Power10 core implements the Processor Compatibility Register (PCR) as described in the Power instruction set architecture (ISA) version 3.1, primarily to facilitate live partition mobility (LPM) to and from previous generations of IBM Power hardware.
Depending on the specific settings of the PCR, the Power10 core runs in a compatibility mode that pertains to POWER9 (Power ISA version 3.0) or POWER8 (Power ISA version 2.07) processors. The support for processor compatibility modes also enables older operating systems versions of AIX, IBM i, Linux, or Virtual I/O server environments to run on Power10 processor-based systems.
The Power10 processors of the Power E1080 server support the following compatibility modes:
Ê POWER8: Enabled by firmware level FW810
Ê POWER9 Base: Enabled by firmware level FW910
Ê POWER9: Enabled by firmware level FW940
Ê Power10: Enabled by firmware level FW1010
2.1.6 Processor feature codes
Each system node in a Power E1080 server provides four sockets to accommodate Power10 single chip modules (SCMs). Three different SCM types with core density of 10-, 12-, and 15-cores are offered. The processor configuration of a system node is determined by one of three available processor features. Each feature represents a set of four Power10 SCMs of identical core density. All system nodes in a Power E1080 server must be configured with the same processor feature.
Table 2-3 lists the processor feature codes that are available for Power E1080 servers. Power10 processors automatically optimize their core frequencies based on workload requirements, thermal conditions, and power consumption characteristics. Each processor feature code that is listed is associated with a processor core frequency range within which the SCM cores typically operate. Also, the maximum frequency that is supported by the relevant SCM type is indicated.
Table 2-3 Power E1080 processor features
Chapter 2. Architecture and technical overview 59