AMD at computex show Fiji GPU with HBM memories that will have very fast and wide IO, 4GB HBM memory into GPU. Which is expected to show up with AMD Radeon Fury X and AMD Radeon Fury. But new AMD Redeon R9 390x will come with 8GB GDDR5 memory type.
As you can see R9 390x will have full unlocked Hawaii XT GPU. It will have 2816 shaders GPU clock speed 1.05 Ghz, 8GB GDDR5 memory with 6Ghz speed and 512bit memory interface 384GB/S memory bandwidth. Compute performance of 5.9TFLOPS not a big jump from 290x 5.6TFLOPS but we have to wait how card perform against NVIDIA cards.