For those moving from 1155/1156/1366 you might be a little surprised at just how much bigger the new CPUs are; it’s little wonder that they require a twin-lever clamping system on the motherboard.
Customer’s old CPU on the right (Intel i7-870, Socket 1156) and their new CPU on the left (i7-3820, Socket 2011). That’s a lot of extra CPU real-estate for all those extra pins – almost 900 more. It’s quite a bit heavier in the hand, too.