P4 ALU (or at least significant parts of it) was double pumped... so parts of a 2GHz P4 were actually running as fast as 4Ghz even back then... Shifts were bad

P4 ALU (or at least significant parts of it) was double pumped... so parts of a 2GHz P4 were actually running as fast as 4Ghz even back then... Shifts were bad however, I think they left out the barrel shifter for some ungodly reason.