The Graphics Cards We Tested
Not all graphics cards are even capable of mining Ethereum. Your AMD or Nvidia GPU should be a fairly recent model, and it's going to be limited by the amount of memory on-board.
The DAG Size Problem
Ethereum mining relies on the creation of a sizable file called a DAG (Directed Acyclic Graph). As time goes on and transactions take place, the number of ETH blocks grows, and the file grows as well. In practice, it gets a little bigger each time it crosses a threshold called a DAG Epoch, meaning every 30,000 blocks representing a window of ~100 hours. Since the DAG relies uniquely on this block hierarchy, it can be pre-generated, allowing miners to catch up. But the DAG must be stored in graphics memory. And that's where some cards run into problems.
Beginning with a certain Epoch, the DAG increased beyond 2GB. At that point, it no longer fit in the on-board memory of most entry-level graphics cards, rendering them ineffective for mining. With a DAG Epoch of 140, cards equipped with 3GB of memory are still usable, but with the size of the DAG continuing to grow, they're the next ones to be eliminated.
So, a graphics card with 3GB will work for now, but if you wish to continue mining Ethereum, you'll want a card with at least 4GB of memory. Boards with only 3GB can still be used with one of the other cryptocurrencies also based on Ethash, but with a smaller DAG size.
Our Contenders
We chose the following cards to test:
How About Mining-Edition Cards?
Certain board partners sell graphics cards specifically for mining. While they're often based on traditional gaming products, they do differ somewhat. For instance, the Sapphire model we're testing is based on an RX 470 Nitro, but with a few alterations. You only get one DVI-D output (certain other mining-specific cards have no display outputs at all), plus there's a second BIOS optimized for cryptocurrency mining. It lowers GPU frequency and voltage, while pushing higher GDDR5 clocks and tuned memory timings.
In practice, the stock BIOS on Sapphire's RX 470 Mining sports a 1288 MHz GPU frequency with Samsung RAM operating at 1850 MHz (and 1V). The purpose-built mining BIOS lowers the GPU to 1206 MHz and pushes the memory to 2150 MHz (with a 0.95V setting).
Test Configuration
| Operating System | Windows 10 x64 Pro 1703 (15063.786) |
| Mining Software | Claymore's Dual Ethereum AMD+Nvidia GPU Miner v9.8* Claymore's Dual Ethereum AMD+Nvidia GPU Miner v10.3 |
| Drivers | Nvidia GeForce Game Ready 388.13Nvidia GeForce Game Ready 384.94** AMD Radeon Crimson ReLive Edition Beta for Blockchain Compute |
*We were not able to re-test Asus' RX 580 OC 4GB with the latest Claymore software version. We still included our previous results for your information, since there are minimal differences in performance between the two builds (almost nonexistent, according to the tests we carried out on other cards).
**We were not able to re-test Asus' GTX 1060 Strix OC 6GB with GeForce 388.13 drivers. However, our other tests performed with GeForce cards show no difference in performance between the 384.94 and 388.13 builds.
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