For mining of cryptocurrency, AMD seems to be much better than Nvidia GPU because of the way AMD GPU is built (Architecture). For the best bang for the buck, you should get the AMD RX 580. It offers max out detail setting at 1080p if you want to game when you are not mining ETH. Also , you should get the 8gb version since ETH requires more vram to mine and 4gb is not going to make the cut for not long. The 8gb version would ensure that you can mine for quite a few years down the road and it would also future proof it.
That is right. The 8GB version is more future proof.
