No question about it, Ethereum is a hot topic these days, with the burgeoning new cryptocurrency currently on pace to intersect and even outpace Bitcoin's market cap valuation. Though it suffered some wild volatility as of late, the open-source, blockchain-based currency platform is on a tear with hobbyists and enthusiasts looking to download and crunch transaction workloads for the ecosystem, on high end desktop PCs. Originally, these machines may have been targeted for gaming but now their graphics cards can also serve as powerful processing engines for crypto-mining, so much so that there's been a run on both NVIDIA and AMD GPUs, driving retailing pricing through the roof on basic supply versus intense demand market dynamics and price gouging. That said, the other metric, beyond GPU cost, that can be a barrier to entry for crypto-miners is power efficiency. Crypto-mining workloads can push cards hard and draw lots of power. As such, there are clear performance-per-watt sweet spots emerging among the current round of graphics cards and the results may surprise you.
HotHardware recently tested eight of the top gaming graphics cards on the market currently, both in terms of raw hash rate (MegaHashes per second) versus total system power draw under load, when mining coins based on the Dagger Hashimoto algorithm that Ethereum (or ETH) uses. It may sound counter-intuitive, but of course all GPUs are not created equal and more powerful doesn't always mean "better" when it comes to mining efficiency for the least amount of power draw, while keeping your electric bill in check. And when you consider these GPUs at scale, since many people literally have mining farms of cards all whirring away, every Watt consumed counts, in addition to raw hash rate.