I see a large number of PowerPC processors (i.e. 8240, 7410, 750, 970, etc.) mentioned in the literature from Freescale and others. Is there any summary available of the relative performance of different processors? I know actual clock speed, board design, software application, and multiple other variables all impact the final answer. It still seems it should be possible to make some generalizations (e.g. processor X is typically 20% faster than processor Y).