NVIDIA is likely citing 1 PFlops at FP 4 sparse (they did this for GB200), so that is 128 TFlops BF16 dense, or 2/3 of what RTX 4090 is capable of. I would put the memory bandwidth at 546 GBps, using the same 512 bit LPDDR5X 8533 Mbps as Apple M4 max.