GoKawiilIBM unveils dual-ISA mainframe core running ARM and z/Architecture natively
At Hot Chips 2026, IBM revealed a next-generation processor built on a 2nm node with 11 cores, each running at a 5.7 GHz base clock. The chip's key innovation is a core that can natively execute both z/Architecture and AArch64 instructions, switching between them within nanoseconds, a result of IBM's April partnership with Arm.
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Mainframe software development has lagged behind x86 and Arm ecosystems, especially for AI workloads, forcing IBM to constantly port tools to its proprietary architecture. By embedding Arm compatibility directly into the core alongside z/Architecture, IBM aims to let businesses run modern Arm-based software on mainframes without sacrificing the extreme reliability those systems are known for, claiming 99.999999% uptime.
- IBM's new core is the first to treat z/Architecture and AArch64 as equal, native instruction sets in one core.
- The chip uses KVM virtualization for Arm instructions while running z/Architecture instructions directly, preserving mainframe-grade reliability.
- Built on a 2nm process with 11 cores at 5.7 GHz, the design aims to unify Arm and mainframe deployments instead of requiring separate systems.
Computer Architecture: A Quantitative Approach (Hennessy & Patterson) — If IBM's dual-ISA core has you curious how a single pipeline can decode two instruction sets, this is the classic text that explains ISA design, pipelining, and virtualization from the ground up. Hennessy and Patterson's book is the standard reference used in university architecture courses, and it makes Hot Chips talks far easier to follow.
See Computer Architecture: A Quantitative Approach (Hennessy & Patterson) on Amazon → Affiliate link — we may earn a commission on purchases, at no extra cost to you. Product picked by AI based on this article; it is not a tested recommendation.Source: tomshardware.com — Jake Roach, 2026-08-24
Published there as: “Hot Chips 2026: IBM's first dual-ISA core natively executes ARM and z/Architecture in the same core; all cores run at 5.7 GHz base frequency — next-gen mainframe AI processor is built on 2nm node with 11 cores”
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