Isn't it possible the Infinity Cache will improve ETH performance? Perhaps once tweaks are done in the mining software?
Infinity Cache only makes the claimed performance improvements when you pair it with a AMD 5000-series CPU and the software/game is designed to utilize Smart Memory Access
This is incorrect those are two separate things. Infinity Cache has driver level functionality for all games, but will only improve once game developers start to utilize it. You con't need an AMD 5000 CPU to use it.