They do. Video here from 7 years ago that talks about it: https://www.infoq.com/presentations/click-crash-course-modern-hardware https://www.infoq.com/presentat

They do. Video here from 7 years ago that talks about it: https://www.infoq.com/presentations/click-crash-course-modern-hardware https://www.infoq.com/presentations/click-crash-course-moder... Basically, they do speculative execution with register renaming to get quick turn-around if the memory is available in cache. It really is quite crazy how much faster the cpu is than memory and what tricks it pulls to get around that problem.