was on sale or else a 270 would have been the choice. Step 12: Mining Config File - GPU Parameters Each series and brand of graphics cards can be optimized using parameters in the config file. The motherboard, CPU, and RAM are all relatively unimportant. Powered risers are necessary when building a rig with this many GPUs. Drill holes in your brace so that you can secure it with cable ties (see image). It looks like all of the current 290 cards are using AMDs reference cooling design at the moment, so brand probably doesnt matter too much. Some 270 cards only have one plug as they require less power. GPUs will have 1 or 2 plugs of 6 pins that deliver the remaining power that they need to run at full throttle. It would be the minimum in order to run Windows and works well for Linux and distros such as bamt. Some motherboard have an on-board power button which is a new development.