> Efficient TSO emulation is crucial (both on Windows and elsewhere) Yes, but this is not in contention...? No one is disputing that TSO semantics in the emula

> Efficient TSO emulation is crucial (both on Windows and elsewhere) Yes, but this is not in contention...? No one is disputing that TSO semantics in the emulated x86 code need to be preserved and that it needs to be done fast, we're talking about the tradeoffs of also having TSO support on the host platform. > The blog claims hardware TSO is non-ideal on Windows only (because Microsoft adapted the ecosystem to facilitate software-based TSO emulation). (Even then, it's unclear if the author quantified the concrete impact) > Hardware TSO is still of tremendous value on systems that don't have ecosystem support That isn't what the author said. From the article: > Another common misconception about Rosetta is that it is fast because the hardware enforces Intel memory ordering, something called Total Store Ordering. I will make the argument that TSO is the last thing you want, since I know from experience the emulator has to access its own private memory and none of those memory accesses needs to be ordered. In my opinion, TSO is ar red herring that isn't really improving performance, but it sounds nice on paper. That is a direct statement on Rosetta/macOS and does not mention Prism/Windows. How correct that assessment may be is another matter, but it is not talking about Windows only. > Those applications would still benefit from ARM64EC (i.e. native system libraries), but the actual application code would be affected quite badly by the TSO impact then, depending on how good their fallback heuristics are. I will have to check this, I don't think it's that bad. JITted programs run much, much better on my Snapdragon X device than the older Snapdragon 835, but there are a lot of variables there (CPU much faster/wider, Windows 11 Prism vs. Windows 10 emulator, x86 vs x64 emulation). I have a program with native x64/ARM64 builds that runs at -25% speed in emulated x64 vs native ARM64, I'm curious myself to see how it runs with volatile metadata disabled.