IBM had 2 discrete Power Architecture hardware lines, based on different Operating Systems:
- OS/400, later i5/OS, more later IBM i
- AIX (on the same hardware it is possible to run Linux as well)
I. 1986-1990 (AS/400 - IBM RT):
In 1986 AIX Version 1 had been introduced for the IBM 6150 RT workstation, which was based on UNIX.
In 1987 for the other product line: OS/400 (later i5/OS and IBM i), the platform (hardware) AS/400 had been released.
II. 1990-1999 (RS/6000):
Among other variants, IBM later produced AIX Version 3 (also known as AIX/6000), for their IBM POWER-based RS/6000 platform. The RS/6000 family replaced the IBM RT computer platform in February 1990 and was the first computer line to see the use of IBM's POWER and PowerPC based microprocessors. Since 1990, AIX has served as the primary operating system for the RS/6000 series.
AIX Version 4, introduced in 1994, added symmetric multiprocessing with the introduction of the first RS/6000 SMP servers and continued to evolve through the 1990s, culminating with AIX 4.3.3 in 1999. RS/6000 was renamed eServer pSeries in October 2000.
III. 2000-2004 (eServer pseries):
IBM eServer was a family of computer servers from IBM Corporation. Announced in the year 2000, it combined the various IBM server brands (AS/400, RS/6000...) under one brand.
The various sub-brands were at the same time rebranded from:
- IBM AS/400 to IBM eServer iSeries, i for Integrated.
- IBM RS/6000 to IBM eServer pSeries, p for POWER
They merged to use essentially the same hardware platform in 2001/2002 with the introduction of the POWER4 processor. After that, there was little difference between both the "p" and the "i" hardware; the only differences were in the software and services offerings. AIX 5.2 was introduced in October 2002.
IV. 2004-2008 (IBM system i and p):
In 2005 announced a new brand, 'IBM System' as an umbrella for all IBM server and storage brands:
- IBM eServer iSeries became IBM System i
- IBM eServer pSeries became IBM System p
With the introduction of the POWER5 processor in 2004, even the product numbering was synchronized. The System i5 570 was virtually identical to the System p5 570. AIX 5.3 was introduced in August of 2004. In May 2007 IBM launched its POWER6 and AIX 6.1 in November 2007.
V. 2008-2010 (Power Systems):
In April of 2008, IBM officially merged the two lines of servers and workstations under the same name, Power Systems, with identical hardware and a choice of operating systems, software and service contracts.
Power Systems is the name of IBM's unified Power Architecture-based server line, merging both System i and System p server platforms, and running either IBM i (formerly i5/OS and OS/400), AIX or Linux operating systems. Power Systems was announced April 2, 2008.
In February of 2010, IBM announced new models with new POWER7 microprocessor and AIX 7.1 in September 2010.
POWER8 is under development at this date.