1. A multiple GPU (graphics processor unit) graphics system comprising: a plurality of GPUs configured to execute graphics instructions from a computer system, wherein each GPU of the plurality of GPUs comprises a plurality of graphics rendering pipelines; a serial bus connector coupled to at least one GPU of the plurality of GPUs, wherein the serial bus connector is configured to removeably couple the at least one GPU to the computing system, wherein the serial bus is operable to hot-plug the at least one GPU to the computer system and enable the at least one GPU to communicate with the computer system through a serial bus; a GPU output multiplexer; and a controller unit coupled to the GPUs and the output multiplexer, wherein the controller unit is configured to control the GPUs and the output multiplexer such that the GPUs cooperatively execute the graphics instructions from the computer system, and wherein the GPUs have asymmetric graphics rendering capabilities, and wherein the controller unit is operable to allocate a first workload to a first GPU of the plurality of GPUs and operable to allocate a second workload to a second GPU of the plurality of GPUs, wherein the first workload is larger than the second workload, wherein the GPU output multiplexer is operable to multiplex output from the GPUs having asymmetric graphics rendering capabilities.