When mining for ETH you really want to get the most hashes per second at the lowest power consumption possible. There are a couple of calculators out there to help you play around with these parameters and see what kind of profit you would be getting.
I bought a power meter and plugged it in to see how much power my rig was consuming when mining. I also installed ASUS GPU Tweak II to be able to control some parameters of the ASUS 1060 DUAL 6GB GPU and HWInfo to get more detailed reading on memory frequencies, temperatures and power consumption. This was from running on stock settings:
I was getting out ~19 MH/s from the card and reaching temperatures of around 66C. The machine consumed about 138W and the GPU was using 100W.
It turns out, these stock settings are not optimal for mining as described in this article. You can lower the power target of the GPU and boost the memory clock significantly to get higher hash rates at lower temperatures and lower power consumption! Almost sounds to good to be true, but have a look:
I was now mining at ~22MH/s at 60C and only consuming 119W instead of 138W and the GPU only drawing 82W. The conclusion is that tuning matters, a lot! Numbers add up quickly when you have a mining rig running 24/7.
I played around a bit with the parameters of GPU Tweak II and found that the memory clock is the one that counts when it comes to hashrate. Underclocking it by 1500 Mhz got me a hashrate of ~12,2MH/s and overclocking it by 1500 MHz got me to 22 MH/s. The power target parameter mainly affected the power consumption, although bringing it down to 50% killed the hashrate as well. Setting the power target at 70% got me the best hashrate per Watt ratio. The GPU Voltage and GPU Boost Clock parameters didn’t do much for the hashrate at all.
Also, it looks like I’m not really utilizing my 750W gold rated PSU. I might try sticking in one more 1060 GPU in there. I wont be able to run the cards in SLI so it won’t improve gaming performance, but it would double the hash rate when mining.