A simple test of whether the Universe is a hologram (or a computer)
Also assume that the universe has finite computational resources. Therefore resources have to be diminished in one location when they are in in demand another location.
The simulation of a complex event, such as some highly involved, very low redundancy, fast moving and extensive event (like some kind of very large very fast collision between two highly involved structures, there are better examples) will result in significant local load on the universe computer.
Given our two assumptions above then we have a measurable result:
Ether the speed of light (or Planck constants) will be diminished in that local region, or they or their product will be diminished in another region.
If the diminishment is local (or within a testable neighbourhood) this can be tested.
If the diminishment is not in a testable neighbourhood, perhaps other experimental constructions will work.