Ethereum forum, they made a calculation and said most GPUs won't be able to mine Ethereum due to DAG limit. Only 4GB and higher will work.
Ethereum forum: https://forum.ethereum.org/discussion/4394/extending-mining-through-the-use-of-sli-for-large-dag-files#latest2GB DAG mid-2017, take it from someone who should know and did the calcs (dlehenky)
If I only had one ETH for every "miner" sitting on the sidelines waiting for PoS to arrive....
