Parallel set up seems to freak about 75% of XS out
A closed water loop behaves pretty much as en electric one. Think of the blocks as resistors, the pump as the battery and the current as flow, if that makes any sense to anyone. For you that are not familiar with electrical circuitry or fluid dynamics, you will just have to trust that it works because it does. As the path of least resistance is about equal flow through both GPU blocks.