TechSpot published Gaming at 4K: GeForce GTX 970 SLI Performance
A quote from the article:
Nvidia's GeForce GTX 970 positioned itself it as an ideal candidate for multi-GPU 4K gaming by outperforming the Radeon R9 290 while undercutting its price too. As expected, AMD was quick to respond with price cuts, which means folks looking to game at 4K have some capable multi-GPU options for as little as $600 to $660.Gaming at 4K: GeForce GTX 970 SLI Performance @ TechSpot