Today were at 768 threads on the latest AMD system. Sub millisecond performance is possible (I don't know with this algo).
If you got a spare 50k kicking around we could set up a test system and find out how likely it is to happen...
If you have a thousand cores running at 2GHz, that's a two billion cycles a millisecond.
An RNG like ChaCha8 can run at about 2 cycles per byte, and extrapolating, 18 cycles for 72 bits. Not far off.