Why do two supposedly different graphics cards rotate an assembly at the same speed?

To answer this question, one needs to know a bit more about how Autodesk Inventor® works. The"Minimum Frame Rate" slider on the Tools > Options > Display tab lets the user control the rate at which the scene updates during interactive operations like rotation, pan, and zoom. • Minimum Frame Rate slider set to Zero: • If one sets the Minimum Frame Rate slider to 0 (see below) Autodesk Inventor® displays all of the graphics data in the scene in each frame update. This is used only as a test mode, to allow us to compare all graphics cards on an even basis. This mode should not be used to compare Autodesk Inventor® performance with that of other products, since it's not the way users generally use the system. • Minimum Frame Rate Slider is not set to Zero • In this mode, Autodesk Inventor® limits the amount of time allowed for each frame. It draws as much of the frame as it can in the allowed time, then it checks to see if the mouse has moved. If the mouse has moved, Autodesk Inventor® ...  more