How does HBM2 throttle 1080p performance? I've seen you post something similar a few times, but can't see the logic.
HBM2 bandwidth is exceptional, and the latency can be either lower or higher than GDDR5x/6 depending on the workload.
This Quora post is quite articulate on HBM2 latency:
https://www.quora.com/In-how-many-c...er-than-current-GDDR5-on-current-GPU-chipsets
Here's a paper on HBM1 performance, note that latency changes for block size:
https://arxiv.org/pdf/1704.08273.pdf
Here is a presentation written by NVidia singing HBM/HBM2's praises for GPU workloads:
https://www.archive.ece.cmu.edu/~ece740/f15/lib/exe/fetch.php?media=dram_for_gpus_talk.pptx
Anyway, cutting to the chase: HBM2 is in theory superior in every way to GDDR5X/6, where a wide parallel bus will always outperform serial buses. It's currently low clock speeds mean that the latency can be higher under certain workloads. However, for GPU's memory latency is not as relevant as for CPU's due to the predictable operations being performed.
HBM2 currently costs more, but that will not always be the case once volumes rise. Further, GDDR6 is a nightmare for board layout and tolerating - it costs non-trivial money to implement.