Cooling?
You should be able to bake bread on top of this arrangement.
More than 3 rows of disks in sequential airflow requires jet turbine levels of airflow to keep the temperature under 50C.
OpenIO has launched its SLS-4U96 product, a box of 96 directly addressed drives offering an object-storage interface and per-drive scale-out granularity. The SLS-4U86 is a 4U box holding up to 96 vertically mounted 3.5-inch disk drives, providing up to 960TB of raw storage with 10TB drives and 1,152 TB with 12TB drives. The …
I wonder why you think that - have you perhaps not been around servers much, especially real datacenters with decent power density?
It's routine to dissipate 300W in a 1u server, so given the same airflow, a 5u box has a 1500W budget, and the drives shown dissipate about 5W when active...