The Sling Shot Physics Test measures CPU performance. It stresses the CPU while minimizing the GPU workload to ensure that GPU performance is not a limiting factor.

The Sling Shot Physics Test has three levels with different workloads. The first level is the lightest and the last is the heaviest. The purpose of the three levels is to extend the performance range for which the test is relevant. 

The Physics Test runs with a fixed timestep at 30 frames per second. The Physics Test always begins with the first level and continues to the next level until either the test is finished or 90 seconds have passed. If a level does not finish completely, it will contribute proportionally less to the final score. The final score is the weighted sum of all levels.

The first level of the test has 8 simulation worlds running in separate threads. Each world has one soft body with 107 vertices and 64 rigid bodies. The rigid bodies are invisible and are there to cause the blast effect to the soft bodies. Additionally, there are 32 CPU simulated particle systems with around 500 particles in each.

The second level of the test adds 8 simulation worlds running in separate threads. Each new world has one soft body with 499 vertices and 64 additional rigid bodies. 

The third level of the test adds another 16 simulation worlds running in separate threads. Each new world has one soft body with 499 vertices and 64 additional rigid bodies. 

Each of the 32 worlds is simulated at 30 frames per second. The whole test takes 16 seconds at 30 FPS. The first level starts at time 0, the second level starts at time 5, and the third level at time 10.

All physics calculations are computed on the CPU. Soft body vertex data is updated to the GPU on each frame.  

The Bullet Open Source Physics C++ Library version 2.83 alpha is used for physics computation.