Just stop. I don't think these are legit at all. Anandtech's Haswell Architecture article would leave me to believe we can expect 10-20% IPC increase depending on workload. Also this: https://twitter.com/FPiednoel/status/296459612377468928 Edit: Also check out some of his other tweets in his timeline, he clearly states that if you have a "healthy" Haswell, under no circumstance will it be slower than IVB. He is Principal Engineer / Performance Architect at Intel so I am inclined to believe him.