TFX stands for "Small Form Factor" and is a type of form factor. TFX power supplies have a different casing form and are thinner than normal ATX power supplies. The underlying technology is no different from that of ATX network components. They are primarily used in small casings, such as for multimedia computers.
Temperature-controlled fan regulation
Fan regulators are used by many manufacturers to keep the fans quieter. Control is performed on a temperature basis. Measurement sensors constantly monitor temperatures (such as on cooling elements). If the temperature is overly high, then the control unit increases the operating voltage for the fan and hence the RPM and air flow.
USC stands for Ultra Silent Concept and was developed by be quiet! for extremely quiet fan operation. The design has been registered with the German patent office. The variety of electronic and mechanical optimisations, such as FDB bearings with copper cores, flow-optimised fan blades and high-quality IC motor control lead to more silent running, best-of-class air flow and very low noise emission.
"Under Voltage Protection", or UVP for short, is a protective mechanism for output direct current. The power supply automatically switches off if the voltage converted by the power supply falls below a defined threshold. This protects the power supply and hardware components against damage.