> The cost of doing it in software is just a highly predictable (not taken) branch after every integer arithmetic operation that the compiler can't prove stays within bounds. The article presents no data on this cost.

The article does mention a 5-10% cost on JavaScript VMs, as one datapoint. And as another, that languages like Rust choose to allow overflow to avoid the overhead, despite preferring the security of not having silent overflows (implying they measured a slowdown they find unacceptable).