Have you checked your warning messages? I suspect you have thousands of "unable to calculate" messages. I doubt you are using Revit to perform hydraulic calculations. You can turn off calculations in piping systems now. This can be a big boost in big models.
Yes, I checked the warning messages. Most of the warning messages are regarding unconnected sprinkler heads or fittings, but I don't see any errors from calculation. Plus, I had already turned off the calculations in piping system and deleted pressure drop and flow in sprinkler family.