Windows is preparing for Intel's biggest x86 change in years, but only Xeon chips will use it at first

What happened

Windows enthusiast Xeno recently uncovered what could be one of the most interesting changes coming to future Windows releases. Big Beautiful Registers: Three years after Intel first introduced the technology, x86 APX extensions are finally making their way into the Windows ecosystem. Intel is a semiconductor and electrical company based in Santa Clara.

Intel is expected to release the first APX-compatible processors in the coming months, when its " Diamond Rapids " Xeon CPUs (the general-purpose processor at the centre of a computer) are expected to debut in the server market. Microsoft's OS may soon offer an option to enable Advanced Performance Extensions (APX) support on compatible hardware, the self-described "Windows Insider since day one" said.

Software Hardware x86 windows insider Windows is preparing for Intel's biggest x86 change in years, but only Xeon chips will use it at first APX doubles x86-64's general-purpose registers from 16 to 32, so compilers can keep more values close to the CPU By Alfonso Maruccia October 26, 2026, 14:06 Add TechSpot Serving tech enthusiasts for over 25 years. TechSpot means tech analysis and advice you can trust .

The new instruction set advancement will initially be limited to Xeon processors, but the performance gains could still be significant. In turn, APX could deliver a significant – although still largely unproven – performance boost for software optimized for x86-64.

Xeno spotted the change in Windows Insider build 29695, suggesting that it could eventually become part of the major "Rubidium" update expected in 2027 as Windows 11 27H2. The user manually enabled the new setting, which is designed to let Windows use APX extensions for "better performance" after a system reboot. – Xeno (@XenoPanther) October 23, 2026 For now, Xeno said, the new option is "for developers" and has no practical impact on how the OS operates.