The code was compiled into two versions: one from a source file with the acceleration flags commented out, producing a regular CPU program, and one with the acceleration flags active, producing a hybrid CPU-GPU program with the forward model calculations being done on the GPU. The code was tested on the same super computing platform on which the CLARREO OSSE currently runs, which is NASA's Pleiades super computer. For all tests, a single "GPU" node of Pleiades was used, which contains an Intel Xeon X5670 processor at 2.93 GHz. The GPU co-processor is an nVidia Tesla M2090 operating at 1.3 GHz. Several timing tests were made to reveal the speedup achieved by the GPU at varying numbers of grid boxes.