It all heavily depends on the cloth settings, the more constraint groups you have enabled, and the more solver iterations for each one, the slower it gets. Supposing 1 iteration for stretch constraints, which is the absolute minimum to simulate something that resembles cloth, 5000 cloth triangles can be simulated in about 6,5 milliseconds. A second stretch iteration almost doubles that time, and if you start adding fancy stuff (bend constraints, aerodynamics, etc) things of course get slower. So, my advice is to start with the bare minimum: deactivate everything except stretch constraints, and then start adding stuff while your ms/frame budget allows it. I'm creating some (pretty complicated) charts so that people get a better idea of what to expect in terms of performance. Btw, at some point multithreading will be thrown in Obi, that should give a noticeable performance boost.