It isn't zeal, it's 15 years past hazy memory of getting different results on different executions in the same supercomputer. The story that went around was the

It isn't zeal, it's 15 years past hazy memory of getting different results on different executions in the same supercomputer. The story that went around was the one I relayed, but certainly your link does a better job explaining things that happen in the user perspective section: https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2025/p3715r0.html#reproducible https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2025/p37... Summarized as, > Most users cannot be expected to know all of the ways that their floating-point code is not reproducible. Glad to know that the situation is defaulting to SSE2 nowadays though.