Ann, that is totally true. When I deactivate all scripts on the sim, Pump IO rises to 20 ms. It takes what it can take apparently. And because I have a lot of "spare time", Pump IO takes this spare time.... BUT that still doesn't explain why it takes more than there really is available. Why is my time dillation around 0.90 and does my sim FPS never reach 45, while on other sims, with much more scripts running and less spare time and Pump IO only 1.0, succeed in having a sim FPS of 45 and time dilation 1.0 ?? I guess no one can really answer that without coming to the sim, but my guess is now that it is because of megaprims and sculpties, altho this doesn't really show in the physics statistics.