IBM 9105-42A
The 9105-42A machine type is the IBM Power S1024, the 4U two-socket Power 10 system reaching 48 cores and 8 TB, and the one where the processor feature decides P20 or P30 software pricing.
The 9105-42A is the machine type of the IBM Power S1024, the largest scale-out system in the Power 10 line. It reaches 48 cores, 8 TB of memory and 102.4 TB of internal NVMe. It is also the Power 10 machine type where the processor feature you pick moves the software tier, and that recurring cost usually outweighs the hardware difference several times over.
A 9105-42A can sit at P20 or at P30. Two machines with the same machine type on the same rack elevation can carry very different annual software bills purely because of which processor module went in the socket. Model the licensing cost of the smaller feature against the larger one before the configuration is fixed, because the tier is not something you can renegotiate later without changing hardware.
IBM 9105-42A datasheet
IBM Power S1024 (9105-42A) published specifications
| Specification | Value |
|---|---|
| Machine type-model | 9105-42A |
| Generation | IBM Power 10 |
| Sockets | 1 or 2 |
| Maximum cores | 48 |
| Memory | Up to 8 TB |
| Internal storage | Up to 102.4 TB NVMe |
| Operating systems | IBM i, AIX, Linux |
| Software tier | P20 or P30 |
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 9105-42A
S1024 processor options
| Cores per socket | Maximum cores | Typical clock range (GHz) | Module |
|---|---|---|---|
| 12 | 24 | 3.40 ... 4.0 | DCM |
| 16 | 32 | 3.10 ... 4.0 | DCM |
| 24 | 48 | 2.75 ... 3.90 | DCM |
The 24-core socket gives the most total throughput at the lowest base clock. Check which side of the P20 and P30 boundary each option falls on before choosing.
Selected Power 10 models were withdrawn from marketing effective 31 July 2026.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 9105-42A
From IBM i
DSPSYSVAL QMODEL returns the model portion and DSPSYSVAL QPRCFEAT returns the processor feature code. Those two values identify a 9105-42A 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 9105-42A is a 4U chassis with two sockets, distinguishing it from the single-socket 4U 9105-41B and the 2U 9105-22A and 22B.
Next steps for a 9105-42A
The tier consequence of each processor option is set out on the Power 10 CPU page, with the full listing at IBM Power S1024. Price it through Power 10 pricing and compare against the newer line on Power 10 vs Power 11.