IBM 9028-21B
The 9028-21B machine type is the IBM Power S1012, the compact single-socket entry system IBM added late to the Power 10 line for small on-premises and edge deployments.
The 9028-21B is the machine type of the IBM Power S1012, and it is the odd one out in the Power 10 family. IBM introduced it well after the original scale-out line, in a half-wide 2U or tower chassis, aimed at small IBM i shops, branch sites and near-edge deployments that were never going to fill an S1014.
It is the smallest Power 10 IBM built: 8 cores, 256 GB of memory and four internal NVMe bays. That ceiling is the whole point of the machine and also its risk. An S1012 sized correctly for a small footprint has very little room to absorb growth, and the upgrade from it is a new machine type rather than a bigger module.
IBM 9028-21B datasheet
IBM Power S1012 (9028-21B) published specifications
| Specification | Value |
|---|---|
| Machine type-model | 9028-21B |
| Generation | IBM Power 10 |
| Sockets | 1 |
| Maximum cores | 8 |
| Memory | Up to 256 GB |
| Internal storage | Up to 12.8 TB NVMe across four internal drives |
| PCIe | Four PCIe Gen5 slots |
| Operating systems | IBM i, AIX, Linux |
| Software tier | P05 or P10 |
| Position in the line | Late Power 10 entry system, introduced after the original scale-out models |
Figures are the published maximums for this machine type. A specific installed system is defined by its processor feature code and activated core count, not by the machine type alone.
Processor feature codes for the 9028-21B
S1012 processor options
| Cores | Typical clock range (GHz) | Module |
|---|---|---|
| 4 | 3.0 ... 3.9 | eSCM |
| 8 | 3.0 ... 3.9 | eSCM |
Exact rated frequency belongs to the specific processor feature code on the machine, not to the model name. Confirm the feature code before sizing or quoting.
Selected Power 10 models were withdrawn from marketing effective 31 July 2026. Installed systems are unaffected, but sourcing a processor upgrade or an MES expansion now depends on availability for that specific feature code. Confirm current supply before building a plan around adding cores.
How to confirm you have a 9028-21B
From IBM i
DSPSYSVAL QMODEL returns the model portion and DSPSYSVAL QPRCFEAT returns the processor feature code. Those two values identify a 9028-21B build exactly, which is what a vendor needs to quote parts or an upgrade.
From AIX, Linux or VIOS
lsconf reports the machine type and model in the first lines of output. prtconf gives the same plus processor implementation and clock speed.
From the HMC
Managed system properties shows machine type-model and serial together with installed against activated cores. On Power 10 those two core numbers frequently differ because of capacity upgrade on demand.
From the bezel
The 9028 prefix is unique to the S1012 in the Power 10 line ... every other Power 10 scale-out machine is a 9105. If the label reads 9028, you have the entry system.
Next steps for a 9028-21B
Processor options across the generation are compared on the Power 10 CPU page, with the full listing at IBM Power S1012. If the 8-core ceiling is the constraint, compare the 9105-22A S1022 and read Power 10 in 2026 before choosing between expanding and moving generation.