Abstract: A lighting fixture with enhanced heat sink performance is provided. The fixture comprises an upper globe portion and a lower globe portion formed of a substantially transparent light transmitting material for emitting light. The fixture comprises a unitary ring heat sink member including an outside surface and an inside surface. The inside surface includes a plurality of mating surface portions having a flat mating face configured for mating engagement with a respective light source board and for selectively positioning of the light source boards. The heat sink member comprises a first material having a volume V defined by: V=(Q*(?*2))/?T, wherein Q is a heat source power, ? is a thermal conductivity of the first material, and ?T is a difference in temperature between a maximum thermal threshold temperature for a light-emitting diode and a maximum ambient temperature.