(R17) I'm in the middle of a 15 hour render so I can't test this, so I'll ask:
I've noticed that restarting an "editor playback" of an emitter changes the way the particles move, especially if one has messed with forces such as Turbulance or Rotation.
If you restart a RENDER, does c4d do a quick recalc so that particles are back on the same track, or does it just start whereever you restart? IOW, is it necessary to bake particle paths before executing a render that will be started and stopped?
"Putting the HARM in 'harmonica' since 2005."
the editor is about speed it just takes whatever it has in a frame and is not accurate with breaks at all. Full render will calculate from the start to ensure accuracy which can take a while if you are restarting a long way in. It's not necessary to cache the particles but it gets rid of the calculation phase at the start of each new render so if you are doing a bunch of starting and stopping it can be quicker to cache.