Well, if you want to prove the simulation argument, all you have to do is simulate a reality for an individual at any time-dilation you like. With the parallel compute capabilities we are increasingly growing, simulating a small section of the universe at a large time-dilation should be within our grasp sooner than we think.
There is a limit to the total computation that can be done in the universe or with a certain limited energy/volume of space. It's caused by the slowness of signals traveling at light speed. They say probably a black hole is the best computational engine there is.
