"The secret to this performance increase is that nearly 60% of cpu instructions have been “retired” by more efficient code:"

Well, where else was the speed-up going to come from?

"You can't actually make computers run faster, you can only make them do less."

-- Unknown (My gratitude if anyone does know the source of this quote)

Clearly, "doing less" does include things like "(re-)fetching a bunch of bits into the cache", but "executing fewer instructions" is definitely one of the most obvious places to start.