I'm getting a performance test score of 151 when using my CPU for the physics. It goes down to 104 when using one of my graphics cards, and they are good cards. After looking at the utilization, it seems that the graphics cards are very underutilized, even when set to calculate the physics. The usage on one card sits at 0% and the other averages 15% usage. I turned vertical sync off. I have the Intel Core i7 5930K with Hyperthreading off, and my graphics cards are two Radeon HD 7950s in Crossfire.
Even though this application doesn't seem to take advantage of Crossfire, I should be able to dedicate one card for the graphics and one card for the physics. The CPU seems to calculate the physics better, though.