IBM demonstrated an unusual processor at the Hot Chips 2026 conference that can directly execute instructions from two architectures (z/Architecture and Arm AArch64) at the same time. The 11-core chip will be produced using 2nm process technology and can operate at clock speeds higher than 5.7GHz.
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The key feature of this development is that IBM did not place separate Arm and Z cores on the same die, nor did it resort to software emulation. AArch64 supports implementation directly on the same processor core that executes z/Architecture instructions. Additionally, each core is capable of using both architectures simultaneously. This will enable IBM clients to run Arm-specific versions of Linux, cloud and artificial intelligence software alongside traditional mainframe trading and database applications. In this way, IBM hopes to combine the broad Arm software ecosystem with the scalability, security and high availability of the Z and LinuxONE platforms.
The processor will come with a set of dedicated hardware accelerators. In particular, there are AI inference blocks that can be used to detect fraud directly during transaction processing, integrated DPU processors that accelerate I/O operations, and separate accelerators for data compression, encryption, and sorting.
Each of the 11 processor cores will receive a dedicated 36 MB L2 cache. In addition, the architecture provides 432MB of virtual L3 cache and up to 3.5GB of virtual L4 cache. This memory organization is designed to reduce latency when processing large databases and intensive transaction loads.
The implementation of AArch64 is entirely in hardware. This processor supports the AArch64 v9.3 architecture, including SVE and SVE2 extensions, and IBM has implemented a total of 2,792 AArch64 instructions. In this case, the Arm code runs in Little Endian mode, while z/Architecture uses Big Endian. IBM also claims to be compliant with Arm SystemReady, allowing existing Arm software to run without modification.
The company has yet to reveal the name of the processor or announce which systems it will debut in. IBM only clarified that the chip is designed for future generations of IBM Z and LinuxONE. Since the current z17 mainframe was released in 2025, and IBM typically updates the platform about every three years, the new processor seems to be the most likely candidate for the next generation of systems, known simply as z18.
IBM mainframes continue to play an important role in the infrastructure of large organizations, especially in the financial sector. Modern IBM Z systems already allow you to use KVM virtualization and OpenShift to run Linux alongside z/OS applications. The new processor will extend this model, allowing s390x and Arm64 workloads to run simultaneously on the same core. According to IBM, switching cores between the two architectures takes only a few nanoseconds.
IBM expects this will allow customers to take advantage of Arm’s vast software ecosystem without giving up their existing Z infrastructure and its reliability, security and transaction processing benefits.
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