1070. Always go with a single card over Crossfire/SLI. The 1070 is almost as fast and is supported by every game. On the other hand crossfire is not supported by every game, and can be problematic. I used crossfire previously and when it works it can be great, when being the operative word. I swapped for a single RX 480 which actually runs a little slower than my prior setup (2 R9 280's) and I prefer it by far because while it gets a few less fps, everything overall runs better.