You make a good point here. The cost of a HD7970 here in Australia is still about $400, so that's a $1600 outlay how long would it take to make back the initial

You make a good point here. The cost of a HD7970 here in Australia is still about $400, so that's a $1600 outlay how long would it take to make back the initial outlay and then you have other factors to take into account like cooling as well and geographical location and price of energy.