It is wrong to say that "Qualcomm's processors are much more power-efficient than their x86 competitors". It is true that Qualcomms processors use less power, but they are NOT more power efficient. Hypothetically, imagine an Intel CPU is using 15W, and a Qualcomm is using 7W. Then the Qualcomm is using less power. BUT, if, e.g. the Intel can finish the same task in 1/3 of the time that the Qualcomm does, then the Intel is more power efficient. This is the reason that ARM chips are hardly found in data centres - they use MORE electricity to complete the SAME tasks. I hope that ARM catches up. There are many articles that explain this problem with ARM power efficiency. Here is an Intro : http://www.datacenterjournal.com/arm-intel-instant-replay-risc-cisc/