1. A method for performing multisampling-based antialiasing in a system that includes a first graphics processing unit (GPU) and a second GPU comprising: rendering a first version of a frame in the first GPU using a first multisampling pattern; rendering a second version of the frame in the second GPU using a second multisampling pattern; identifying edge pixels in the second version of the frame; and combining pixels in the first version of the frame with only those pixels in the second version of the frame that have been identified as edge pixels to generate a combined frame.