Maybe somebody can enlighten me regarding how connecting 2 videocard blocks in parallel works. It appears that the top card acts as an input, but I really don't see how the water circulates through the top waterblock - it will flow straight down through the SLI fitting into the second block, where it will circulate and exit the videocard. Unless there exists significant back-pressure at the exit of the bottom waterblock to force the water up the SLI fitting into the top waterblock, I just can't see how the top videocard is being cooled.