One example of legacy baggage is the fact that x86 doesn't reorder loads and stores as freely as ARM. It would be better for optimization, but it would break t

One example of legacy baggage is the fact that x86 doesn't reorder loads and stores as freely as ARM. It would be better for optimization, but it would break the creaky old software that is the lifeblood of the platform. Another example of "evoluationary heritage" is the fact that x86 chips require a northbridge and/or southbridge, whereas with ARM chips, everything is integrated on the chip. This was one reason why Atom-based designs often weren't that low power-- the CPU itself might be low-power, but the glue logic was thirsty. There is evidence that Intel is trying to change this, and put everything on one chip. I'm not trying to say that x86 will never succeed in mobile. I don't have a crystal ball. I'm just saying that the burden of proof is on Intel to prove that it can be cost and performance-competitive in that space. And I am not the only skeptic-- Apple and Microsoft use ARM for most of their mobile offerings.