An anonymous sources shared some more details about AMD's next-gen GPUs with WCCF Tech. Expected to be released in 2016, the upcoming lineup will include the Greenland flagship and the high and mid-end Ellesmere and Baffin GPUs. There's also talk about a "Vega10" chip, but it's uncertain what this is, perhaps it's a power-efficient version of Greenland, similar to the R9 Nano product.
These new chips will all be made on a FinFET process, but it's still uncertain which foundry will manufacture them, it's either 16nm at TSMC or 14nm at GlobalFoundries. One of the key focuses is reportedly power efficiency, thanks to the switch to the smaller node as well as the adoption of HBM2 memory.
Lastly, it looks like AMD will be giving special attention to power saving in the next generation – an initiative it started with Tonga, continued with the R9 Nano and will probably perfect with the FinFET generation of GPUs. This could mean that we can expect more power efficient variants – in the mainstream as well as enthusiast market segments. Infact, AMD is counting on this very fact and is pretty confident on design wins for Ellesmere and Baffin – which should target the performance market. The source further mentions that the company is very pleased about the transition to DirectX 12 and Vulkan – claiming it to be a game changer and very good for Radeons and FirePros in the long run. The new low level APIs should truly help leverage the power of AMD’s GCN and improve Radeon and FirePro positioning as (relatively) future proof GPUs.