AMD Polaris graphics cards, which are considered fourth generation GCN, won't ship until mid-2016 but will feature:
- Polaris GPUs will be on a 14nm FinFET process.
- DisplayPort 1.3 for support to drive 4K @ 120Hz.
- HDMI 2.0a support will finally be found for Radeon GPUs.
- 4K HEVC/H.265 encode/decode support.
- Big improvements in performance-per-Watt.
- New hardware features like a primitive discard accelerator, instruction pre-fetch, memory compression, and hardware scheduler.
Hopefully I'll have more Linux-specific details to share soon as my (twice-they-canceled) RTG briefing takes place over GPUOpen, etc.