IBM System i
System i is the name IBM used for the AS/400 line from 2006 until April 2008, when the brand became IBM Power Systems and i5/OS became IBM i. For AI work the hardware is the catch, because System i machines use Power 5, Power 5+ or Power 6 processors and IBM states that IBM i 7.3 will not support Power 6 systems, so no System i can run a release IBM's current IBM i documentation covers.
What is IBM System i?
System i is a brand name, not a different computer. It is the same product line that started as the AS/400 in 1988. In 2005 IBM created one umbrella brand called IBM System for its servers and storage, and in 2006 each family took a new name under it. The eServer iSeries became System i. The eServer pSeries became System p. The zSeries became System z and the xSeries became System x.
Think of it like a street that keeps getting renamed. The houses never move. Only the signs change. If you work in a shop that still says System i, you are talking about the same family of machines that other people call AS/400, iSeries or IBM i.
IBM's own book for the era is the IBM System i5 Handbook IBM i5/OS Version 5 Release 4, dated January 2006. IBM says it was distributed to support the latest System i announcements of 31 January 2006, and it covers the i5 520, 550, 570 and 595 models. IBM describes those models as the first servers in the industry based on the leading-edge IBM POWER5 64-bit microprocessor. The operating system of that period was i5/OS, which is what OS/400 was renamed to in 2004.
One product line, five names
- 1988IBM announces the AS/400, running the OS/400 operating system.
- 2000The line is rebranded eServer iSeries under IBM's eServer brand.
- 2004The line becomes eServer i5 and OS/400 is renamed i5/OS. The 5 points at the Power 5 processor.
- 31 January 2006IBM's System i5 Handbook is distributed to support the System i announcements of this date, covering the i5 520, 550, 570 and 595.
- 14 September 2007The System i 570 becomes available as the first System i server using the dual-core Power 6 processor, at up to 4.7 GHz.
- 2 April 2008At the COMMON conference IBM retires the System i and System p brands, creates IBM Power Systems, and renames i5/OS V6R1 to IBM i 6.1.
The 2006 line is from IBM Redbooks publication SG24-7486, the IBM System i5 Handbook, January 2006. The September 2007 and April 2008 lines are from IT Jungle reports dated 24 July 2007 and 7 April 2008, all read for this entry on 14 October 2026.
Can a System i run today's AI tools for IBM i?
Not on that hardware. The AI tooling IBM and its partners ship for this platform expects a current IBM i release, and IBM's own upgrade planning pages rule out every processor a System i could have. The table below is IBM's wording, not a vendor opinion.
What IBM says each release needs
| IBM i release | What IBM says about older processors |
|---|---|
| IBM i 7.3 | IBM i 7.3 will not support Power6 systems. |
| IBM i 7.4 | IBM i 7.4 is not supported on any IBM Power servers with IBM Power7 and IBM Power7+ and earlier processor technology. |
| IBM i 7.5 | IBM i 7.5 is not supported on any servers with IBM Power8 and earlier processor technology. |
| IBM i 7.6 | IBM i 7.6 is not supported on any servers with IBM Power9 and earlier processor technology. |
Each row is quoted from IBM's Planning to upgrade to IBM i pages on ibm.com/support, read on 14 October 2026. Power 6 is the newest processor any System i model used, so the ceiling lands below every release in this table.
Read the first row again, because it does the work. Power 6 was the newest chip a System i ever used, and IBM says IBM i 7.3 will not support it. IBM's current IBM i Services reference documents releases 7.3, 7.4, 7.5 and 7.6. So a System i cannot run any release in IBM's current documentation set. Replacing the hardware is the entry fee, not an upsell.
Running is not the same as supported. An old machine in a corner may still boot and still run payroll. That does not mean IBM will service the release, and it does not mean a new tool will install. Ask IBM or your business partner for the support status of your exact model and release before you plan any AI project around it.
Does the code still move forward?
Yes, and this is the good news. The RPG and COBOL programs written in the System i years are the same languages running on IBM i today. OS/400, i5/OS and IBM i are one operating system line with three names, so the programs carried across each rename without a rewrite.
That matters because the current AI code tools read source code. IBM calls watsonx Code Assistant for i a coding assistant that is purpose-built to accelerate the modernization of IBM i applications, and says it is capable of providing context aware RPG code explanations. IBM says it is built on a flagship IBM Granite code model that is fine-tuned for RPG and IBM i. RPG is the language most business programs on this platform are written in. Your System i era source is exactly what that kind of tool is trained to read.
What should a System i shop do first?
Three checks before you plan any AI work
- Find out which processor you actually haveThe brand on the front panel is not the answer. You need the Power generation inside. Power 5, Power 5+ and Power 6 are all System i era chips, and all three sit below what IBM supports for current releases.
- Find out which release you are runningA System i was sold with i5/OS. If you are on i5/OS or IBM i 6.1, you are below the releases IBM documents today. Write down the exact release level before you call anyone.
- Price the move, then the toolNew hardware and a current release come first, because the AI tooling assumes a supported platform. Get that number before you evaluate any assistant, so the AI budget is not hiding a hardware project.
The processor and release limits in these steps are IBM's, quoted from the upgrade planning pages in the table above.
Related Terms
iSeries
iSeries is what IBM called the AS/400 line from 2000 under its eServer brand, and it is still the word many shops use for any IBM i machine. The distinction matters for AI work, because IBM states that IBM i 7.1 is not supported on the iSeries family, so true iSeries-era hardware stops at IBM i 6.1 and cannot run a release current AI tooling expects.
AS/400
IBM's original 1988 midrange business computer platform; the term is still used informally to refer to IBM i systems and shops even though IBM has rebranded the hardware and OS multiple times since.
OS/400
OS/400 is the original name of the operating system IBM now calls IBM i. It shipped with the AS/400 on August 26, 1988, became i5/OS in 2004 and IBM i in 2008, so the RPG, COBOL and Db2 for i objects that today's AI tools read sit on one unbroken operating system line.
IBM i
IBM's operating system for Power servers running traditional AS/400-lineage business applications, with Db2 for i built directly into the OS.
RPG
Report Program Generator, the primary business application programming language on IBM i and its AS/400 predecessors, still running the majority of production logic in most IBM i shops.
IBM Power 10
IBM's Power processor generation that preceded Power11, announced August 17, 2020 and shipping from September 2021, the first Power chip to embed Matrix Math Acceleration into every core for on-chip AI inferencing without a separate GPU. IBM began winding down new Power10 sales in February 2026.
IBM Power 11
IBM's current generation of Power processor and server hardware, announced July 8, 2025 and generally available July 25, 2025, carrying forward Power10's on-chip Matrix Math Acceleration and becoming the first Power generation to support the IBM Spyre Accelerator card.
watsonx Code Assistant for i
IBM's November 2025 preview announcement of an AI code assistant purpose-built for RPG on IBM i. The preview track was superseded by IBM Bob, which reached general availability in March 2026.
IBM i Technology Refresh (TR)
An IBM i Technology Refresh, or TR, is how IBM adds new function to an IBM i release a shop is already running: it arrives as one Technology Refresh PTF Group, and installing it leaves the release level and the machine code level unchanged. TRs are also where the platform's AI groundwork shows up, because IBM's own IBM i 7.6 TR2 notes from July 2026 document the Code for IBM i editor extensions and the IBM Bob Premium Package for i, and list 17 new IBM i Services an agent can read over SQL.