Blender 2.78 Cycles rendering is broken when using GPU compute with 7xxx series.
4xx series are rendering fine using the same drivers 16.9.1.
https://developer.blender.org/T49371
https://developer.blender.org/T49019
There needs to be roadmap for developing OpenCl to be backward compatible on across all GCN cards or splitting driver openCL version based on GCN architecture.
There is new experimental microdisplacment feature and hair rendering using GPU in Blender which works on 4xx but not on 7770, 7870, 7950, 7990 cards using same drivers.
