IBM announces a dual-architecture processor that runs Arm and IBM Z instructions on the same core

Sources: IBM Newsroom, HN 49455471
Summary: IBM announced the processor at Hot Chips on 2026-08-24, the first processor milestone from the IBM and Arm collaboration formed in April 2026. IBM states that the chip does not contain separate Arm and IBM cores, and that each of its 11 cores, on a 2 nm node at more than 5.7 GHz, natively executes Arm and IBM Z or Arm and LinuxONE instructions concurrently. IBM labels the release a statement of future direction subject to change, so no shipping date follows from it.
Why it matters: It would let Arm-native Linux run alongside z/OS on the same machine, so software would not need an s390x port to run there.
Follow-up: Whether IBM states a shipping date or a product name, and what the toolchain and hypervisor story is for mixed-ISA workloads.