If you sue for too little, the case will get summary judgement, but that doesn’t really seem like a risk in this case unless there is a specific law that makes this clause unenforceable.

On Linux, you run windows programs through wine, which is an additional layer that can theoretically slow down the program.

Also, windows supports certain constructs like io completion ports or WaitForMultipleObjects that historically haven’t been emulated efficiently on Linux since it lacked comparable primitives, although those specific ones have been greatly improved in recent years with io_uring and FUTEX_WAIT_MULTIPLE.

There have been similar issues with direct3D since wine used to have to emulate it in OpenGL, but with vkd3d, wine has more opportunities to efficiently implement the d3d apis.

Basically wine being slower was the norm until quite recently.