IBM has detailed a next-generation mainframe processor whose 11 cores can natively execute both IBM Z's s390x and Arm's 64-bit AArch64 instruction sets. Announced Monday at Stanford University during Hot Chips 2026, the 2-nanometer chip runs above 5.7 GHz and is the first concrete hardware milestone from IBM and Arm's collaboration established in April. Unlike heterogeneous designs that use separate core types, IBM integrates both instruction sets into every core without emulation. The capability is designed for KVM and Red Hat OpenShift environments, not z/VM, creating a potential migration issue for enterprises and vendors invested in the older hypervisor. The processor supports Arm SystemReady compliance, AArch64 version 9.3 instructions including SVE and SVE2, and a mode transition that IBM says takes roughly one nanosecond. IBM also previewed a next-generation Spyre accelerator with 96 gigabytes of HBM3e, about 4 terabytes per second of bandwidth, 16 active AI cores plus one redundant core, FP4 and MXFP4 support, and PCIe Gen6. The system has no announced commercial name, price, licensing terms, or delivery date, although industry analysis points to around 2028. IBM said its Z and LinuxONE platforms run 68% of the world's production IT workloads and are used by 77 of the world's top 100 banks, while Arm's developer community exceeds 22 million people.