The 7zip code needed to change because it was counting cores by looking at affinity masks, and that limits it to 64. It also needed to change if you want optim

The 7zip code needed to change because it was counting cores by looking at affinity masks, and that limits it to 64. It also needed to change if you want optimal scheduling, and it needed to change if you want it to be able to use all those cores on something that isn't windows 11. But for just the basic functionality of using all the cores: >Starting with Windows 11 and Windows Server 2022, on a system with more than 64 processors, process and thread affinities span all processors in the system, across all processor groups, by default That's documentation for a single process messing with its affinity. They're not writing that because they wrote a function to put different processes on different groups. A single process will span groups by default.