This device has a fully switched fabric allowing comms between any of the 256 "superchip" clusters at 900GB/s. That is dramatically faster than a direct host to GPU 32-lane PCI-E connection (which is crazy), and obviously dwarfs any existing machine to machine connectivity. The actual usability of shared memory across the array is improved significantly.

I mean...nvidia has obviously been using DMA for decades. This isn't just DMA.