For the saving in power consumption you could buy 4 ARM socs per year ; )
Check Odroid XU3 it is on desktop level.
The older U3 is already faster than a X1000 ...
Compile FS-UAE GLES and you are done with AEONS systems.

this is old
http://forum.odroid.com/viewtopic.php?f=13&t=952

http://linuxgizmos.com/odroid-hacker-board-jumps-to-faster-octacore-soc/

x86 way to boring and PPC is dead except for special uses. Nintendo could replace the Gametablet of the WiiU with one with a 8core ARM system and stream the games from it to the wiiU -> this would be cheaper and way more modern.