alt Hacker NewsRubin has 22TB/s of memory bandwidth vs Blackwell's 8TB/s. NVLink 6 doubles interconnect speed. Plus they're moving to 3nm from ~4nm.
(Previously this comment said Rubin did native NVFP4, but Blackwell does too! Rubin just also trains with native NVFP4, which Blackwell does not.)
Moving to lower bits is not a slam dunk, the model itself might degrade too much