To ensure accurate thermal results, we installed the same hardware in each case in virtually the same way. Components included the Asrock Fatal1ty 990FX Professional, Phenom II X6 1100T, Prolimatech Megahalems in passive mode (i.e. no fan actively dispelling heat), Inno3D GeForce GTX 580 OC, half a dozen Western Digital Scorpio Blue 500GB hard drives, and OCZ's ZX 1000w power supply.
We also loaded the H440 with 11 hard drives using our modded trays to see how much of an impact that had on cooling performance.
The H440's idle temps are good with the Phenom II X6 1100T and its passively cooled Prolimatech Megahalems getting enough airflow regardless of whether six or 11 hard drives were installed. That said, at around 30 degrees it was running about 10 degrees warmer than the best cases we have tested and that is likely due to the air being warmed by the hard drives before reaching the CPU cooler.
It is much the same situation for the GPU which idled at around 40 degrees though that said even the best cases hover around 33 to 35 degrees.
Temps soared under full load though the NZXT H440 still performed well, keeping the CPU temperature quite low at under 80 degrees. The GPU did run 10 degrees hotter than some of the better performing cases with six hard drives installed, but that's not outrageous by any means.
As expected, our case mod didn't help the situation and with 11 hard drives installed the temperature increased to 88 degrees, a few degrees hotter than the highest result we have recorded with the Inno3D GeForce GTX 580 OC. Still, the temperatures are within safe limits and a side door fan would really help solve the issue of a packed H440.