AMD is betting on the long term. HBM is the future because of packaging and power savings. the ability to have shareable memory on die is huge. imagine 4+ GPUs on one card. with vulkan and directX12 handling mgpu much better AMD could have an advantage down the road. that is how they're innovating. the current nvidia iteration (1080) isn't much different then Fermi (GTX 480) if you think about it.