with very restricted airflow to the fan with a card plugged into the PCI slot, which would also increase noise possibly. (I like to try keeping at least one full slot of space between a Vid card & its cooling unit in cases these days, years ago, was a different story, but since about 3 or so years ago with my 9700 Pro, on up to my current 8800GTS, like to have adequate airflow to my cards.)