They're not going to beat any modern amd64 based chip for some time. A 2ghz ARM is nowhere near comparable to a SandyBridge or even a Bulldozer in terms of raw power. Aside from just the difference in interconnects (say, built in triple channel DDR3-1866 and PCI-X 2.1), the branch prediction, SIMD units, and so on are just not there in the ARM chips. Gigahertz just don't matter that much (try comparing a 2.2ghz i7 to a 3.4ghz Bulldozer, for instance).
Power consumption will be lower, and performance per Watt may even still be way better, but raw performance will not be.
?????? Cisc-simd is not better than Risc-mimd, ARM has faster FPU. The problem is that ARM runs 8integer32bit+8float32bit wile AVX runs 4complexInteger64bit(like8simple64)+16float32bit(8 float64bit). AVX is almost 2 times faster/thread but this will change with ARM-V8 and they will be equal. Second the issue is not ARM but x86-Cisc replacement. Read my previous post with Arm and Mips. Loongson3C has 16cores with 32integer64bit+32float64bit per core, this equals 64coreAVX and 128coreAVX in streamProc only with 20W and 3x the efficiency of an ARM plus emulation instructions, so I prefer a dual-Mips in my phone. Third there are many others like PCMOS(probabilistic) or NISC-accelerators like ZMS40 that accelerates an ARM by 4times. It is over for Intel, Cisc exist only because it was difficult to emulate it but that is in the past. Intel-Microsoft will not close any more knowledge any more. I run Linux-Wine-Winetricks in any of my Computers, even ARM-QEmu-Wine, even to my quadcoreMips Chinese Laptop.