Glossary

IBM Power8 Glossary

IBM Power8, IBM i, and Power hardware end-of-support and migration terminology, defined in plain English.

A

• AIX — IBM's UNIX operating system for Power servers, commonly run alongside or instead of IBM i on the same Power8 hardware.

C

• CDIMM — Custom DIMM, IBM's memory module format used on Power8 enterprise-class systems (E850, E870, E880), predating the DDIMM format used on Power10 and Power11.
• CPW — Commercial Processing Workload, IBM's relative-performance benchmark for IBM i systems, used to compare processor options across Power generations.

E

• End of Service — The date IBM stops providing standard hardware maintenance, machine code updates, and security patches for a given server model.
• End of Service Life — The point at which a vendor (or the market) considers a product life-cycle fully closed, sometimes used interchangeably with EOS but technically the broader, final milestone.

H

• Hardware Management Console — The appliance or virtual appliance used to manage partitions (LPARs), firmware, and virtualization on IBM Power servers.

I

• IBM i — IBM's integrated operating system for Power servers, the direct successor to OS/400, commonly run on AS/400-lineage hardware.
• IBM Power Virtual Server — IBM's cloud offering for running IBM i, AIX, and Linux Power workloads on IBM-managed infrastructure without owning physical hardware.

L

• LPAR — Logical Partition, an independently running operating system instance (IBM i, AIX, or Linux) on a physical Power server managed by PowerVM.

P

• Power10 — IBM's 2021-generation Power processor and server family, a full two generations ahead of Power8 and a fully supported, currently sold migration target.
• Power11 — IBM's current, 2025-generation Power processor and server family, the longest-runway migration target off Power8.
• Power8 — IBM's 2014-generation Power processor and server family, spanning the entry S812 through the flagship E880, now fully past IBM's standard end-of-support window.
• Power9 — IBM's 2017-generation Power processor and server family, the direct successor to Power8 and a common first migration step off it.
• PowerVM — IBM's virtualization hypervisor for Power servers, used to run multiple IBM i, AIX, and Linux partitions on a single physical system.

R

• rPerf — Relative Performance, IBM's benchmark estimate for AIX and Linux workload throughput, analogous to CPW but for non-IBM i operating systems.

S

• Software Tier — IBM's processor-feature-linked licensing tier (P05 through P30) that determines IBM i software pricing on a given Power system.

T

• Third-Party Maintenance — Vendor-backed hardware support and parts replacement for a server model after its manufacturer's own end-of-service date.

V

• VIOS — Virtual I/O Server, the specialized PowerVM partition that shares physical storage and network adapters across other partitions on a Power system.