do you not understand that the computation power in bitcoin is used as the matter to compensate for growing computational capacity?
definitely I was not clear enough.
ok to say it in other words. It does not matter how much computation power you got per electricity consumption. eventually, to catch up, every other miner will get the same rig as you and then the only way to compete will be to increase the number of those rigs you got. hence the power consumption will grow to previous level because of rapid difficulty growth that is used to consume any computational power you can throw to it. No matter how much you optimize, bitcoin generation will always consume as much power as miners can put their hands on.
this is somewhat like the arms race... and it's just as pointless. but it can't be stopped. this is an intrinsic flaw of the bitcoin design unfortunately.
Yes, eventually low power, high density miners will win and GPU miners will lose out. How many 4x6990 power hungry mining rigs can one put in a normal house? how to deal with the heat? the noise?
How many cool, efficient and silent FPGA boards can be run?
There will be a new technology and a tipping point to make GPU obsolete. It may not be today, it may not be fpga, maybe it is ASIC? but the day will come and power and efficiency will be a major factor.