The HBM2E memory chips offer up to 460 GB/s bandwidth, plus they are 50% more energy efficient and come in a 30% smaller package compared to the HBM2 models. With such an improved bandwidth, the HBM2E chips are expected to significantly improve performance for Exascale computers and high-end GPUs.
https://www.notebookcheck.net/SK-Hynix-starts-mass-production-for-16-GB-HBM2E-DRAM-chips.478926.0.html