Power consumption really doesn't matter at current mining profitability, unless you are paying a lot for power.  Tuning power consumption might be relevant later to extend the life of equipment, but right now you should be optimizing output not power consumption.  My rigs pay off their monthly power consumption in 1-2 days of mining, bringing that down slightly and losing a big chunk of income makes no sense.

I have 3x R9 290 Tri-X OC running at over 945KH/s, and 1x running at 930KH/s.  (The 930KH/s won't take the memory overclock, so it runs at 1250).  Max temp is 75 degrees at 80% fan.

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Regarding RAM... WTF are you guys talking about?  I have my 4 cards running with 4GB of whatever-was-cheapest DDR3 RAM.  If you need more RAM for mining, you're doing something wrong.