It is extremely unlikely that the Universe is a simulation for a wide variety of reasons, foremost amongst them being expense
Unless our simulator are fooling us about the expense of computational power.
Deliberate "fooling" may not even be required. Are Redstone Computers colossal and slow because Notch was trying to deceive some Minecraft denizens? It seems to simply be a necessary fact of "emulation" that any computer built out of physics X is going to be no faster than the computer required to simulate physics X.
If it is... I hope they do not crash the system with the test.
http://www.huffingtonpost.co.uk/2012/12/12/physicists-universe-simulation-test-university-of-washington-matrix_n_2282745.html
Be sure to check out the actual reseach papers linked in the article! I would have linked to them directly, but the article is full of follow-on links of considerable interest.