Some early rumors about AMD's RDNA 2 video cards are making the rounds. Official information from AMD reveals these GPUs will be made on a 7nm+ process and it's believed we can expect video cards based on these chips in the second half of 2020.
Everything below is rumor and speculation. One of the rumors is that the next-gen Radeon cards may be much higher-end than the current Navi-based models, and that they may feature the new HBM2E memory. Depending on the memory configuration, this could result in cards with up to 920GB/s of memory bandwidth.