LPAR performance impacts

The impact of running in an LPAR is not significantly different from running on a similar processor in SMP mode.

The hypervisor functions running on a system in LPAR mode typically adds less than 5% overhead to normal memory and I/O operations. Running multiple partitions simultaneously generally has little performance impact on the other partitions, but there are circumstances that can affect performance. There is some extra overhead associated with the hypervisor for the virtual memory management. This should be minor for most workloads, but the impact increases with extensive amounts of page-mapping activity. Partitioning may actually help performance in some cases for applications that do not scale well on large SMP systems by enforcing strong separation between workloads running in the separate partitions.