Why not 26H1? Does 26H1 have a more modern and streamlined kernel. Does 25H2 (26H2) have more features for x86-64? Why not 25H2 (26H2), given that Microsoft says it is intended for newer processors?
26H1 is not a mainstream release, it will be next year, when it fuses with 26H2 into, expected, 27H2. You can install it on your system and test drive it.
I’m interested in the actual functional differences, performance, compatibility, and stability on x86-64, because most people simply repeat Microsoft’s statement that it is not intended for x86-64, even though that is clearly not the whole story.
Most real enthusiasts here already have tested it on their x64 hardware (it's just another windows). best to do the same yourself.
I am very satisfied with 26H1. I installed in two of my machines. It works and performance better than 25H2. Difference is very not notizable, but it is more stable.
I have none BSOD in none of these machines: One is a desktop AMD Ryzen 7 5700x with ASUS Prime B550M-A and 32gb RAM at 3600. Other is ASUS TUF gaming laptop 7 years old also with AMD Ryzen CPU. The only issue was a ramdom slow of system, but It was problem of a bug inside bios system. Asus resolved with a correct new bios. I have no issues from then.
There are several uncertainties. How well does the new kernel actually work with older processors? Does it provide full backward compatibility and avoid any deep kernel-level issues, such as problems with the scheduler? Can 26H1 be considered as stable as 25H2, given the significant difference in the amount of telemetry Microsoft receives from users of these versions? Are all issues discovered and fixed in 25H2 also fixed in 26H1? Is 26H1 essentially a near-complete copy of 25H2 with additional instruction support for newer processors, or is it an entirely different kernel with added support for older processors?
+1 Same suggestion. Since Dec25 to date, installed 26H1 in all of my PCs, plus others, no issues whatsoever; better than earlier 24/5Hx IMO. Many other users here have said the same already.
That is a debatable statement. How can you determine whether it is a general system-wide issue or just an isolated problem specific to your setup.
I don't play *Wuthering Waves* myself, but I installed Windows 11 26H1 for two friends—one using a Intel Core i7-13700K and the other a AMD Ryzen 5 3600. Both encountered the exact same issue: *Wuthering Waves* would crash to the desktop after about 20 minutes of play. Strangely enough, however, playing *Black Myth: Wukong* (which runs on Unreal Engine 5) on Windows 11 26H1 resulted in absolutely no errors.
A huge number of games run on UE4. If there were an obvious issue specifically with 26H1, we would most likely already know about it. The different matter is that low-level drivers, or specific versions of those drivers, may not work correctly on 26H1. This is exactly the question that remains open, because no one can say for certain whether there are any differences in the kernel’s behavior or internal logic on x86-64 systems between 25H2 and 26H1. It is even possible that it operates through an emulation layer for instructions that are not natively supported by arm64 processors.