New AMD drivers hint at more Polaris GPUs to come
The recent RX 490 rumors may not be all that implausible. Now that the new AMD drivers are finally available, users have discovered the names of two unknown GPUs in the graphics driver for Mac OS Sierra designated as Polaris 10 XT2 and Polaris 12. It can be deduced that both are not referring to the same GPU and since code referring to Vega GPUs can be found as well, it's possible that future Vega GPUs will run on largely the same drivers as existing Polaris GPUs.
Another possibility is that AMD may be developing new GPUs specifically for Apple hardware. While AMD GPUs are already available on certain MacBook SKUs, developing new Polaris hardware only for Apple devices seems unlikely for the chipmaker.
The Polaris architecture is AMD's current design for the Radeon 400 series and also serves as the basis for the recently released Playstation 4 Pro. The aggressive performance-per-Dollar of the latest Radeon GPUs has boosted AMD's market share in the sector to 29.9 percent as of November 2016 from around 19 percent a year earlier. Despite this, AMD currently has no direct competitor to the high-end GTX 1070 or GTX 1080 Pascal GPUs from Nvidia.