My favorite example of this is how Windows NT has had async IO forever, while also being notorious for having slower storage performance than Linux. And when Linux finally got an async API worth using, Microsoft immediately set about cloning it for Windows.
Theoretical or aesthetic advantages are no guarantee that the software in question will actually be superior in practice.
ASync I/O isn't limited to just storage, though. It's /all/ I/O.
And yes, the layered storage stack does have a performance penalty to it. But it's also infinitely more flexible, if that is what you need. Linux still lacks IOCP (which io_uring is not a replacement for).
Windows' VMM and OOM is also generally much better.
Pretty much what I was thinking of. My understanding from reading some commentary in this area is the Linux implementation is yet a little botched due to how it handles waiting threads.
The windows NT kernel is in many ways a better design. However they allow third party device drivers, and run on all kinds of really terrible hardware. Both of them will cause the system to be unstable through no fault of the system.
Don't get me wrong, NT also has its share of questionable design decisions. However overall the technical design of the kernel is great.
It would be much unlike Microsoft if they didn't bring Win32/Win64 compatibility along for the ride somehow, and very stupid also, because as you say that is the real core of Windows in a lot of ways.
I have no idea what they're planning or why, just guessing, as they seem to be bringing Linux and Windows closer together all the time.
> It would be much unlike Microsoft if they didn't bring Win32/Win64 compatibility along for the ride somehow, and very stupid also, because as you say that is the real core of Windows in a lot of ways.
This requires NT API compatibility due to applications using NT API. Despite Microsoft telling devs don't use the NT API, devs use the NT API and Microsoft makes adjustments to ensure compatibility.
> I have no idea what they're planning or why
Clearly, because the whole idea not only makes no engineering sense, it makes no financial sense. They need to build the NT kernel anyway -- it runs the entirety of Azure services!
> Makes no sense to dump a superior kernel and executive for Linux.
At this point in time, having programmed deep in the internals of both Linux and Windows, I think it is probably incorrect to call either kernel an inferior or superior one.
I mean, it was true for both of them at some point (Overlapped IO was great on Windows and missing on Linux, for example) but today, in 2026, the only differentiating factor is the userland experience.
I’ve had more hard crashes and BSODs on Windows than any other OS. And I use Linux & Mac more than Windows. Not sure how it’s superior.
More advanced APIs which allow more fine-grained interaction between system and application IF you can figure out how to use them
My favorite example of this is how Windows NT has had async IO forever, while also being notorious for having slower storage performance than Linux. And when Linux finally got an async API worth using, Microsoft immediately set about cloning it for Windows.
Theoretical or aesthetic advantages are no guarantee that the software in question will actually be superior in practice.
ASync I/O isn't limited to just storage, though. It's /all/ I/O.
And yes, the layered storage stack does have a performance penalty to it. But it's also infinitely more flexible, if that is what you need. Linux still lacks IOCP (which io_uring is not a replacement for).
Windows' VMM and OOM is also generally much better.
> this is how Windows NT has had async IO
Pretty much what I was thinking of. My understanding from reading some commentary in this area is the Linux implementation is yet a little botched due to how it handles waiting threads.
The windows NT kernel is in many ways a better design. However they allow third party device drivers, and run on all kinds of really terrible hardware. Both of them will cause the system to be unstable through no fault of the system.
Don't get me wrong, NT also has its share of questionable design decisions. However overall the technical design of the kernel is great.
They might use the NT kernel and their own version of the Linux userland.
I'd be open to the idea, if the kernel were open sourced (MIT licensed?) so I could play with it too.
Why do that when Win32 is what everyone wants?
We’ve already had NT + Linux userland; that was WSLv1.
I think if we're talking about "what everyone wants", Windows 11 obviously isn't it, so that's not necessarily the driving force here.
As I said, everyone wants Win32. What flavor is up to debate, everyone has their own incorrect opinions.
It would be much unlike Microsoft if they didn't bring Win32/Win64 compatibility along for the ride somehow, and very stupid also, because as you say that is the real core of Windows in a lot of ways.
I have no idea what they're planning or why, just guessing, as they seem to be bringing Linux and Windows closer together all the time.
> It would be much unlike Microsoft if they didn't bring Win32/Win64 compatibility along for the ride somehow, and very stupid also, because as you say that is the real core of Windows in a lot of ways.
This requires NT API compatibility due to applications using NT API. Despite Microsoft telling devs don't use the NT API, devs use the NT API and Microsoft makes adjustments to ensure compatibility.
> I have no idea what they're planning or why
Clearly, because the whole idea not only makes no engineering sense, it makes no financial sense. They need to build the NT kernel anyway -- it runs the entirety of Azure services!
> Makes no sense to dump a superior kernel and executive for Linux.
At this point in time, having programmed deep in the internals of both Linux and Windows, I think it is probably incorrect to call either kernel an inferior or superior one.
I mean, it was true for both of them at some point (Overlapped IO was great on Windows and missing on Linux, for example) but today, in 2026, the only differentiating factor is the userland experience.
For me, Windows loses this hands down.