There’s no easy answer. Branch prediction is a key enabler for other kinds of speculation. Modern CPUs can have dozens of ops in a partially executed state. Thi

There’s no easy answer. Branch prediction is a key enabler for other kinds of speculation. Modern CPUs can have dozens of ops in a partially executed state. This lets them, e.g., simultaneously fetch many lines of memory that are going to be needed soon, under the assumption that a branch will/won’t be taken. If you can’t predict branches, you won’t be able to keep nearly so many ops in flight, and the whole apparatus for speculative execution starts to make a lot less sense. Everything is workload dependent, but I suspect you’re more in the 100x than 5x range after the knock-on effects.