Power And Heat
The following chart is a little difficult to follow, so I'll break it down like this: the blue bar represents our PC on its own, the red bar is the TurboBox on its own, and the black bar is our PC plus the TurboBox attached.
Naturally, in half of the configurations, there's a missing red bar. This is because the TurboBox isn't being used when we plug our graphics cards into ASRock's X79-based motherboard. In the other half of the charts, the PC bar is incredibly short. That is the result of applying a heavy bitcoin mining load to graphics cards in the TurboBox, which doesn't affect the PC all that much.
As you can see, the TurboBox/PC combo uses about 100 to 150 W more than the PC alone. There's some overhead to accommodate the extra hardware, which we'd expect.
Although using the TurboBox increases power consumption, the cards themselves run cooler as a result of the NA255A's optimized airflow. Moreover, the PC's other components don't end up being subjected to additional heat from a multi-GPU configuration on the motherboard.