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Exxact's Standalone Validation Suite is a proprietary test adapted from the GPU engine within the AMBER Molecular Dynamics Software Suite. Developed by Ross Walker, the principal developer of the AMBER GPU software, the test works by repeatedly running all atom molecular dynamics simulations (MD) of varying size. There are 3 different size of test designed to stress both the GPU itself and the GPU memory. For each test size a simulation is run that consists of millions of MD steps, each comprising a large combination of single and double precision floating pointing calculations as well as fixed precision integer arithmetic. The calculation includes pair wise electrostatic and van der Waals interactions, Fourier Transforms, inverse R squared calculations, pair list sorts and integration. This computation pattern uses all parts of the GPU and also stresses the GPU memory. At the end of a fixed number of steps for each run, which averages between 15 and 30 mins the final coordinates, energies and velocities of the atoms are recorded. The calculation is then repeated from the same input parameters and again after a fixed number of steps the final coordinates, energies and velocities of the atoms are recorded. The AMBER GPU engine is designed to be bitwise reproducible which means that a simulation started from identical conditions should give identical results. Any variation in the final results is thus an indication of either a bad GPU or bad GPU memory. The test is run for a total of 24 hours and is very effective at identifying faulty GPUs. So effective in fact that it is credited with identifying design flaws and insufficient frequency margins on 5 different NVIDIA GPU models and NVIDIA now includes a variation of this code as part of their chip design testing process. In addition to checking that all GPUs give consistent results the performance of each GPU is tested using the same code. Performance between repeat runs and between GPUs is compared and determined to be within acceptable tolerances before a system is shipped. This approach effectively identifies both faulty GPUs, for example with faulty power and temperature regulators, and any GPUs that might have insufficient cooling due to air flow restrictions, fan issues etc.