@HoneyBadger that memory recall is very impressive

. The case is a Silverstone DS380:
The motherboard is a mini-ITX one with only one PCI slot which is positioned at the lower of the two PCI brackets of the chassis. The upper bracket is unoccupied, and that's how I had space to mount a small fan on top of the LSI heatsink. As you can imagine, the fan blew air straight into the PSU. I don't know whether the chassis has enough airflow. I read the DS380 wasn't particularly good with cooling the HDDs, but there is a workaround I'm fine with. I don't know whether it will do good with supplying sufficient airflow to the HBA.