@tubetime wow, same! (for robots.) These look like the non-GPU versions, so entirely fanless (there's a thicker model that has the GPU in "cartridge" that plugs into a PCI riser, with 2 fans in the GPU sub-box itself, but still none in the main system, just that huge heat sink.) We mounted ours vertically, with a *lot* more clearance from the heat sink (and explicit testing of GPU airflow, which was an interesting challenge.)