If you have a simulated virtual world completely isolated from the real world, does it matter if you simulate it at normal speed or 1/1,000th speed to the ones

If you have a simulated virtual world completely isolated from the real world, does it matter if you simulate it at normal speed or 1/1,000th speed to the ones inside the simulation? I think not. We already see this with existing simulations, though they are of much simpler objects than conscious beings. If I simulate water sloshing in a bucket, it doesn't matter how long the simulation runs, the results are the same. Now, I may add in short cuts to make it closer to real time to support practical applications which leads to different results, but a slower machine running the same shortcuts will see the same differences.