"Huang said that the future Volta GPUs would have an aggregate of 1TB/sec (that's bytes, not bits) of bandwidth into and out of the stacked DRAM, and added that this would be enough to pump an entire Blu-Ray DVD through the memory in 1/50th of a second."
You were OK until you mentioned "an" entire Blu-Ray DVD. The big caveat to this massive bandwidth is that a single component only sees a tiny fraction of it. It would be more accurate to say that if you happened to have a DVD already divided into several thousand shards then you could stream each shard past a different (and isolated) processing unit in that fiftieth of a second. Obviously that's less impressive. Actually processing that data as a coherent whole will take longer.