The page you linked just link to 2 further pages, one stating that pure Cortex-A8 core under heavy load takes <300mW while pure A9 core takes <250mW per cpu, in power-optimized mode, while at the same time having two cores (so like.. two cpus? so 250mW would change to 500mW for whole chip, thus more than A8? so even that statement would be wrong? or am I misinterpreting something?). Other poster, however wrote that in fact one should compare whole SoCs and clearly noone over there did that publicly, even the post you're probably relating to. And there is no OMAP4-OMAP3 comparison over there either, I still don't know where you got that info from...