Lately we've seen thermally controlled products becoming very popular and for a simple reason really, users are tired of noise. When gaming or running the cpu hard it be necessary to have the fans in the case run at a higher speed generating more airflow, however when sitting idle or surfing it's not necessary to have this additional noise. Till now users were able to control this by installing a product like a Bay Bus which would let the user manually adjust the fan speed via a rheostat type knob. Technology in this area has evolved and now the fans are smart enough to adjust themselves eliminating the need for units like a Bay Bus to be installed.