[gendoikari]

Moreover, the simulation speed would not be related with any "speed" inside the simulation. If the processing speed decrease, the simulation will be slowed, but inside nobody would possibly notice it. If you stop the simulation, everything is stopped, anybody would be "frozen", and there's no way to detect something like that inside the simulation.

[bemmu]

Exactly. Maybe to calculate one iteration of our universe normally would take a second for the "outside computer", but because of very heavy load it now takes a year. We'd be none the wiser.