Robin may have been assuming abundant memory and scarce CPU time? I agree though that unless memory costs are very low this is a problem in the examples.
Robin may have been assuming abundant memory and scarce CPU time?
He's not saving on CPU time (i.e., total number of instructions executed), but substituting more, slower processors for fewer, faster processors and also using more memory. We don't see a lot of this today. For example render farms and data centers all use essentially the fastest CPUs available. Some operations might back off a few notches from the bleeding edge in order to save money, but it's not even close to 2x much less 21x. My earlier "doesn't seem plausible" may be too str...
Lecture at youtube.
Sorry - haven't watched it yet so no summary, but I expect it to be fun.