Keep an eye on power. ARM, in general, has a useful-work-per-watt number that is very hard for x86 to hit. If useful-work-per-rack-slot is equal, and the powe

Keep an eye on power. ARM, in general, has a useful-work-per-watt number that is very hard for x86 to hit. If useful-work-per-rack-slot is equal, and the power is lower, ARM has a good way to attack the rack.