A recent test of eight of the top gaming graphics cards on the market  done by HotHardware, shows the most effective Ethereum miners currently on the market, both in terms of raw hash rate (MH/s) versus the total system power draw under load.

Keep in mind, more powerful doesn’t always mean “better” when it comes to mining efficiency.  This is due to the fact that the less amount of power your graphics card draws, the lower your electric bill will be.  It is also worth noting that the higher the hashrate of the graphics card, the more ETH will be mined.

NVIDIA GeForce GTX 1070 HotHardware.com

NVIDIA GeForce GTX 1070

The current top gaming graphics card, NVIDIA’s GeForce GTX 1080 Ti, delivers the highest Ethereum hash rate but it also consumes drastically more power under load when mining, versus more midrange cards like the GeForce GTX 1070 or AMD Radeon RX 480. Furthermore, with a bit of memory clock and power target tuning, the GTX 1070 can deliver a higher hashrate, while still maintaining a much lower power draw than the 1080.

GPUs Benchmarked In Ethereum Mining
HotHardware.com

GPUs Benchmarked In Ethereum Mining

When you look the numbers, including power draw, the GeForce GTX 1070 cards appears to be the best performance-per-watt GPU currently on the market.  An honorable mention goes to  the AMD Radeon RX 480 and RX 580 coming in close to the profitability of the 1070 and at lower costs.