10.4.6 Energy Delay Squared Product

Martin, Nystroem and Penzes argue that $ET^{2}$ is a voltage independent metric that is better than the energy delay product [64]. For reasons explained in Section 3.5 this research uses $ET^{2}$ merely as a metric that favors performance at the cost of energy.

Figure 10.6 compares the $ET^{2}$ efficiency of the perception processor against its competition. Since this metric favors performance over energy, in most cases the Pentium outperforms the XScale unlike the situation in Figure 10.5. The perception processor outperforms the Pentium on average by a factor of 405 while it is 1869 times better than the XScale. The ASIC is only 29 times better than the perception processor.

Figure 10.6: Process Normalized Energy Delay Squared Product ($ET^{2}$)