AnandTech:
GeForce GTX 1080, on the other hand, is not faster at FP16. In fact it's downright slow. For their consumer cards, NVIDIA has severely limited FP16 CUDA performance. GTX 1080』s FP16 instruction rate is 1/128th its FP32 instruction rate, or after you factor in vec2 packing, the resulting theoretical performance (in FLOPs) is 1/64th the FP32 rate, or about 138 GFLOPs.