Here is my reasoning --<p>An Atom Z530 1.6GHz core has almost exactly 2X the Dhrystone MIPS of a 1.0GHz ARMv5TE-based network SoC (I actually ran it; those are not bogus vendor marketing #s).<p>A9 probably has much higher IPC than ARMv5 -- but I doubt it's high enough to beat an Atom running at 60% higher frequency; that is a hell of a gap to close architecturally. I also suspect Atom has higher DRAM bandwidth; the A4 pkg looks a bit small for x64 DRAM. Finally, A4 may or may not have more than 1 core; Atom definitely has 2.<p>I am talking pure performance, not performance per watt, which is not interesting to me in this situation. I can almost always find AC if I'm using something iPad-sized.