That is a different algorithm, though, right? They didn’t rewrite the rust code to use matrix multiplication, so it’s no longer a direct comparison, and is inst

That is a different algorithm, though, right? They didn’t rewrite the rust code to use matrix multiplication, so it’s no longer a direct comparison, and is instead comparing unoptimized rust with a less efficient algorithm to super optimized C++ with a more efficient algorithm (being called from python). In which case, IMO, it’s fairly surprising that the rust implementation is only 2x slower.