1. A graphics processing system comprising: a single arithmetic logic unit operable to execute a command thread selected from either of at least one pixel command thread and at least one vertex command thread; an arbiter, coupled to the single arithmetic logic unit, operable to select the command thread from either of the at least one pixel command thread and the at least one vertex command thread and provide the command thread to the single arithmetic logic unit; a renderer coupled to the single arithmetic logic unit; and a scan converter coupled to the single arithmetic logic unit.