At the moment if you want high end desktop performance you have no choice but Intel and AMD. I run a few apps that can easily max out even high end CPUs so I just got myself a high end laptop with a rather nice quad core i7.

The apps are Photo editing, Movie editing and Synth plug-ins.

One of those apps (photo editing*) is actually disc bound and I suspect movie editing* is too - even with an SSD. Only the synth plugin is purely CPU bound.

*In both cases this is exporting of the finished photos or movie. This will max out the processor but it will then spend more time accessing the disc.

ARM parts are mainly designed for mobile so are limited by the power available which tends to be very low. This however is changing. The A15 is designed to handle higher clocks and it'll be appearing in servers where you get wall socket power. Build them on a high speed process and they should be pretty potent. They wont be top end i7 level but they'll be a lot faster than today's ARM cores.

In the mean time I guess you'll have to do with the 2GHz dual A9 Rockchip just announced (shipping this year).