Before I begin, I'd like to provide some relevant background information.
My bedroom has a tendency to trap heat, and is usually the warmest room in the house. It also faces west, which means that in the summer months, the room can get unbearably hot unless the central AC system is turned on full-blast, complicated by the fact that there is only one HVAC register in the room. With the Astaroth desktop's power draw often exceeding 400W under full gaming load, converting most of this energy into heat, keeping the room at a reasonable temperature during long gaming sessions can be challenging.
This led me to the question: How do I get the system to run cooler and use less energy without unacceptably degrading game performance? Read on for the answer...