In the specifications, the number of 3.5" drive bays (internal) is 9 x ... I would expect a sensible placement of the drive bays so that the 3.5" drives are in the airflow of the two front fans and can thus be cooled on both sides. In the photos, however, I don't see any drive bays at all, but a yawning void. Where exactly are these 9 drive bays?