Energy dissipation in general purpose processors

In this paper we investigate how super-scalar issue and pipelining affect the energy-delay product of general purpose processors. We show that for idealized machines pipelining gives approximately a 2/spl times/ improvement in energy-delay product, while super-scalar issue only improves the energy-delay product by a small amount. We then show that real processors are roughly half as efficient as the idealized machines. We also show that improving the efficiency will be difficult since the overhead is distributed among many units, none of which represent a significant fraction of the energy dissipation.