Not everything has to be computed in every computation cycle. Most things are already pre-computed and the operations to do the corrections would mostly be simple additions and multiplications.

Written in hand coded assembler language: Maybe 100 cycles. Actually Quake from 1997 used a very similar prediction for network coding and not joking, it took less than 60 cycles and the very same code has been used to guide the IRIS-T system - which by the way uses an 1.4Ghz ARM Quadcore.

Written in Dotnet: Your computer is to old. No matter which computer.