sorry for taking your topic for my silly questions ...

You say that the rendering takes 100% of the cow's system, but you also can keep working on them ... so that means it is not using all the system resources. And since you say it is a running in background I keep wondering ... are these cows really working at its 100% for my render purposes?

Is not there a way you can make them work like S. XV slaves with no time to think in anything else than my renders?

you're saying CG sunlight is actually based on a real thing????