Yeah, it's next-level stuff, here. He said around 12 billion instructions which sounds like a lot, but with our current processors, not that much work for the CPUs.
More specifically, a billion instructions is one giga-instruction. A 2 GHz processor can execute roughly 2 billion instructions per second (this is a very rough estimate, thanks to superscalar, pipelining, uops, yada yada). So 12 billion (typical) instructions will take around 6 seconds to run.
This sort of thing is handy when profiling: see a function taking a billion instructions? Half a second of CPU time. And this ratio hasn't changed all that much in quite a while (what has changed, of course, is how many threads can execute simultaneously).
