Right. Generally, memory accesses in real-world software are unpredictable enough (no matter how good the compiler is) that single-threaded execution is always

Right. Generally, memory accesses in real-world software are unpredictable enough (no matter how good the compiler is) that single-threaded execution is always going to get a big boost from OOO. An interesting question is why Intel believed otherwise when they created IA64. I think there's a strong case that publication bias and other pathologies of academic compuer science destroyed billions of dollars in value, and would have killed Intel had it not had monopoly power.