I'm making a program that involves making models of and working with arbitrary systems (or programs). What is the most computationally efficient Turing complete system to model these in?
By "arbitrary system", I mean anything with inputs and outputs. It could be anything from a function that adds 1 to the input to a complicated video game.
What is the most computationally efficient (or fastest) Turing complete system to simulate these arbitrary systems in?
For example, if you were to simulate any program as a test (for example, a 4-bit adder) in some Turing complete system, what system would result in that test program getting simulated the fastest?
User D.W. suggested using asymptotic worst-case runtime as the metric for evaluating the different systems' computational efficiency.