Bug 1: We were purporting to calculate milliseconds per tick, when we
*should* have been computing ticks per millisecond.
Bug 2: Instead of computing either one of those, we were _actually_
computing femtoseconds per tick.
These two bugs covered for one another on x86 hardware, where 1 tick
== 1 nanosecond. But on M1 OSX, 1 tick is about 41 nanoseconds,
causing surprising results.
Fixes bug 40684; bugfix on 0.3.3.1-alpha.
