Good point joe. That was the other point I thought of posting. A lot of times you can see just as good, if not better, performance gains by reducing latency (waiting) rather than just simply increasing output.
I look at it like this -> Hypertransport Technology is a good example, picture a tunnel with cars driving through it back and forth, but they have to share lanes, so one car has to wait for another car to move before it can advance. If you increase the speed limit that's not going to do much good if the cars have still have to wait for a car to move before they can go. (The cars are bits of data if you didn't figure it). With hypertransport the cars have dedicated lanes for incoming traffic and lanes for outgoing traffic(it sends data on both the rising and falling edges of the clock signal). This decreases the wait times (latency), now increasing the speed limit will have a better effect without the waiting.