Although it is a change in specifications, probably not too high a percentage of users will decide. SSE 4.2 instructions support all AMD Ryzen and Intel Core “i” processors; however, there may be problems in older ones. Indeed, SSE 4.2 is required (SSE 4.1 or SSE 4a is not enough).
At Intel, SSE 4.2 support appeared on processors I don’t smoke (e.g. Core i7-960), in the older generation Penryn (eg Core 2 Quad Q6600) is still missing. In other words Core “i” won’t have a problem, but Cores where the number series is preceded by letters (usually Q, X or E) will. From Atoms is needed Silvermont and newer (Airmont, Goldmont, Tremont…), on the other hand older (Bonnell, Saltwell…) is not enough.
Intel Penryn processor wafer
There will be no problem with (Ry)zens or construction machines in AMD’s offer (Bulldozer, Piledriver, Steamroller, Excavator), so most APUs are also “dry” – with one exception. The first generation of small nuclei (Bobcat) does not support SSE 4.2, it came only with the generation Jaguar (and its derivatives as Puma+). K10 / K10.5 architectures (ie Phenoms and older) do not support SSE 4.2.
If you were to run a platform based on VIA processors (which is probably only a risk for a single reader, but we can summarize it for completeness), there will be no problem with the Nano QuadCore C4000 and Eden X4 series. Conversely, SSE 4.2 is missing from the Nano 3000, X2 and QuadCore series (lower than the mentioned C4000).
In practice, many systems with these processors will also have other limits, as a result of which they are not enough to achieve compatibility with Windows 11, but many of them could be bypassed, which will probably be a problem due to the requirement for SSE 4.2.
