AMD needs to improve the following aspects to be able to compete with Nvidia:
- Flexible float precision cores. GP100/GP102 has this feature already, and Vega too. This doesn't matter for current games, but it will in the future.
- Improved scheduling. AMD have great theoretical performance, but are not able to feed the cores efficiently.
- Improved rasterization. Nvidia has since Maxwell employed tiled rasterization to minimize memory bandwidth constraints, achieve cache locality and resource dependency problems. The Vega slides mention "Draw Stream Binning Rasterizer", we'll have to see what this means.
But as always, real performance matters.