IBM AIX
AIX is IBM's UNIX operating system for IBM Power hardware, the sibling of IBM i on the same servers and the source of the AIX runtime that IBM i ships as PASE for i. On Power 11 it needs AIX 7300-03-01 or higher to run in Power11 compatibility mode, and its AI packages arrive as RPMs from the AIX Toolbox for Open Source Software.
What is AIX, and how is it different from IBM i?
AIX is IBM's own version of UNIX. It runs on IBM Power servers, the same family of machines that run IBM i. Picture one Power server as an apartment building. IBM i can live in one apartment and AIX in another, in the same building, at the same time. IBM describes AIX as a trusted UNIX operating environment designed to support mission-critical business operations, which is a formal way of saying it is built for work a company cannot afford to lose.
- AIX and IBM i are two separate operating systems. They are not versions of each other.
- Both run on IBM Power hardware, so one machine can host either or both.
- PASE for i is the AIX runtime built into IBM i. IBM says it lets you run many AIX applications on the IBM i operating system with little or no change.
- So an AS/400 shop meets AIX in two places: as a separate system next door, and as the runtime hiding inside IBM i.
AIX release timeline
- 1990AIX 3 launches for IBM's Power-based computers, initially the RS/6000, built on AT&T UNIX System V.2 and V.3 with some BSD 4.2 features.
- Sep 10, 2010AIX 7.1 ships. Its support ended April 30, 2023.
- Dec 1, 2015AIX 7.2 ships. Technology Level 5 followed in November 2020.
- Dec 10, 2021AIX 7.3 ships, the current release.
- Dec 2025AIX 7.3 Technology Level 4 arrives, with fix support listed through December 31, 2028.
IBM adds new function in Technology Level updates, usually once a year in the fourth quarter.
Which AIX level does Power 11 need?
AIX levels and the processor mode they can run in on Power 11
| AIX level | Mode it can run in |
|---|---|
| AIX 7300-03-01 or higher | Power11 compatibility mode |
| AIX 7300-03-00 or lower | Power10 compatibility mode |
| AIX 7200-05-10 or 7300-02-04 or higher | Power9 and Power9_Base compatibility mode |
A compatibility mode tells the processor which generation of features to show the operating system. An older AIX can still run on a new Power 11 machine, just with an older set of processor features.
Where does AI software on AIX come from?
AIX gets its AI and machine learning tools the same way it gets the rest of its open source software: as RPM packages from the AIX Toolbox for Open Source Software. IBM calls that the official site for downloading GNU and open source tool packages for AIX, and recommends dnf as the package manager in place of the older yum. An RPM is a prebuilt software package, like a sealed kit you install instead of compiling it yourself.
- onnxruntime-python3 1.22.1, listed by IBM as the Python 3 bindings for onnxruntime, which runs an already trained model so it can answer questions.
- faiss-python3 1.12.0, a Python package for similarity search, the kind of lookup behind a vector store.
- dnf 4.23.0, available for AIX 7.1, 7.2 and 7.3.
The AIX Toolbox RPMs are built per release, with packages published for AIX 6.1, 7.1, 7.2 and 7.3. Check that a package exists for your own AIX level before planning around it.
Can AIX use the Spyre Accelerator?
Not according to IBM's own requirements page. The IBM Spyre Accelerator for Power needs a Power 11 system and lists Red Hat Enterprise Linux 9.6, 9.8 and 10.2 as its operating system. AIX is not on that list, and neither is IBM i. To run AI models on the Spyre card today, you run them under Linux on that Power 11 machine.
IBM also lists Podman and Quadlet as the container runtime, a minimum of 512 GB of memory, 10 cores and 600 GB of storage, and up to 24 cards per logical partition. A logical partition, or LPAR, is a slice of one physical server that runs its own operating system. Card drawers holding 12 cards need Red Hat AI Inference Server 3.5 or later.
Related Terms
IBM PASE for i
PASE for i is the AIX runtime built into IBM i, and it is where the open-source software behind most AI work on the platform actually runs. It ships as option 33 of 5770-SS1, has been a no-charge option since V5R2M0, and it hosts the yum-installed Node.js and Python builds under /QOpenSys/pkgs, including the Mapepire server that IBM's IBM i MCP Server connects through on port 8076.
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.
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.
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.
IBM Spyre Accelerator
A PCIe4 AI inferencing card IBM ships for IBM Z, LinuxONE and Power11 systems to offload generative and agentic AI workloads from the main processor. On Power11 it is driven from a Red Hat Enterprise Linux or Red Hat OpenShift AI partition, and as of September 2026 IBM has not documented a way to use it from an IBM i partition.