notice 2 of the modules are stacked. 1 of the radiators is flipped upside down to accommodate this stacked setup. also, i'm glad to see that 2 of the fans have been moved to the back to provide exhaust. also note that we have 2 Seasonic PSU's in place to drive the 3 modules.
Yes, I got two questions on this already so let me clarify: there are three modules in that image of the Sierra. Two are on the bottom layer (side by side), and one module seated above.
This let us have better airflow in the case (and more room for the SeaSonic PSUs).
Why two power supplies? How are 3 modules connected to two power supplies? Are they producing redundancy? If so how is that achieved? Is each power supply connected to each board (would imply two power connections pwe board)? Wouldn't one large power supply be sufficient, cheaper, and take up less space?