IBM eServer® p5 servers with POWER5™ processors contain new technologies called simultaneous multi-threading and optionally, Micro-Partitioning™. AIX 5L™ Version 5.3 contains support for these new technologies. This white paper describes these new technologies and the AIX 5L support for them.
Micro-Partitioning is a mainframe-inspired technology that is based on two major advances in the area of server virtualization. Physical processors and I/O devices have been virtualized enabling these resources to be shared by multiple partitions. There are several advantages associated with this technology including finer grained resource allocations, more partitions and higher resource utilization.
Simultaneous multi-threading is the ability of a single physical processor to simultaneously dispatch instructions from more than one hardware thread context. It is a feature of the POWER5 processor and will be available at the same time as shared processors. There are two hardware threads per processor.