Microsoft has introduced official support for Intel’s Advanced Performance Extensions (APX) in Windows 11 Insider build 29695. While no consumer PCs can currently take advantage of the instruction set, the software toggle lays the groundwork for Intel’s next-generation “Nova Lake” processors ahead of their planned release.
X user Xeno (via Neowin) found the option hidden in the preview build. Although you can “enable” it after uncovering it, Xeno noted that turning it on didn’t do anything.
Testing on the Rubidium codebase suggests Microsoft is preparing the feature for a future update like Windows 11 27H2. Intel originally debuted APX in July 2023 to enhance 64-bit execution efficiency, recently publishing architecture specification version 9 in August 2026 and enabling the full instruction set in GCC 15.
As an extension to the x86-64 ISA, APX doubles the number of general-purpose CPU registers from 16 to 32. Compiled code that uses APX can also take advantage of dedicated paths and the extra register capacity. According to Intel, compiled code using APX contains around 10% fewer instructions, which reduces CPU cycle consumption and frees up system resources despite slightly larger instruction lengths.
Besides register expansion, the extension introduces three-operand instructions using a New Data Destination register to cut out extra data moves. New conditional operations and a No Flags feature also help compilers reduce branches and bypass costly branch mispredictions. Furthermore, PUSH2 and POP2 instructions streamline register saving, rounded out by a new 64-bit absolute direct-jump instruction.
KitGuru says: Nova Lake will probably be the first CPUs to make use of APX, so it will take some time before we see how it works. Do you think APX will bring notable performance improvements to applications that can use it?
