NVLink is the most notable (>600GB/s GPU-to-GPU communication) whereas the best case scenario on 30x0/40x0 GPUs is peer-to-peer PCIe (~30GB/s) and average case is routing PCIe through the host (~15GB/s)
3090 does 4x nvlink each way, ~100 GB/s bidirectional data
Oh huh I didn't know about that!
Normally it's architectural changes such as FP8 support as noted in the submission, but in that case newer mid-range GPUs like the A10 and the L4 (https://www.nvidia.com/en-us/data-center/l4/) should be supported but aren't.