Intel wants feeback for a proposed 64-bit only CPU architecture called x86S

Right now, 64-bit apps and operating systems are becoming the norm, rather than the exception, for Windows users. Microsoft stopped offering 32-bit versions of Windows to its PC OEM partners in 2020. However, current CPUs, including ones made by Intel, still support running apps and OSs with 32-bit platforms.

Now, Intel is starting to at least think about developing a CPU architecture that just runs 64-bit apps and operating systems. The company quietly posted an update to its webpage with info, and a whitepaper on this 64-bit CPU, which it currently calls x86S.

Intel points out that right now, current CPUs have to go through older legacy modes. However, they offer "little utility in modern operating systems besides bootstrapping the CPU into the 64-bit mode."

Intel claims that a 64-bit CPU would help to simplify both the software and hardware designs of such a chip by getting rid of older software development ideas. Here are some of the things a 64-bit chip would eliminate from current systems:

• Using the simplified segmentation model of 64-bit for segmentation support for 32-bit applications, matching what modern operating systems already use.
• Removing ring 1 and 2 (which are unused by modern software) and obsolete segmentation features like gates.
• Removing 16-bit addressing support.
• Eliminating support for ring 3 I/O port accesses.
• Eliminating string port I/O, which supported an obsolete CPU-driven I/O model.
• Limiting local interrupt controller (APIC) use to X2APIC and remove legacy 8259 support.
• Removing some unused operating system mode bits.

Intel also believes virtualization hardware is advanced enough now that if some users still want to access older 16-bit and 32-bit operating systems and apps, they can do so with virtualization products.

It should be noted that Intel currently uses x86-64 in its CPUs. This is a 64-bit version of its x86 instruction set that's also known as AMD64, in a cross-licensing deal with rival CPU maker AMD. If Intel moves forward with the new x86S architecture, it might have some impact on the cross-licensing deal, which is probably also a reason why the company is looking for feedback.

The whitepaper (in PDF format) goes into a lot more detail about this proposed 64-bit CPU. Intel is releasing it now to get feedback from its many partners and the PC ecosystem. While the company is at least putting some of its ideas to paper, it may be a long, long time before Intel is actually ready to release a true 64-bit CPU to the masses.