As GPU mining made CPU mining non-profitable, at some point in time more specialized mining hardwares (FPGA and ASIC) would make GPU mining non-profitable.
When is GPU mining considered not-profitable?
Considering $1000 rig, $0.2 per kWh and one year break-even period, at which difficulty does GPU mining become non-profitable?
Or, what is the formula to find out "max non-profitable Mhash" for given parameters like, rig cost, power consumption, investment break-even period, difficulty, exchange rate, etc. (please ignore redundant parameters, and include more parameters if required.)
Or, whats the current "max non-profitable Mhash"?
Or, what is the required current energy efficiency (Mhash/J = millions hashes per joule) for mining to be profitable?
(energy efficiency; 1 joule of energy is 1 watt during 1 second: 1 J = 1 W*s)
For given parameters, Max. Non-profitable Hash Rate, is breakeven point for hash rate after which mining becomes profitable.