glxgears is a very simple example of OpenGL, its purpose is only to show that the renderer is working and a relative
speed it is capable of.. a benchmark or test suite it is not.
One good way to test out heavier load rendering is to install a game! Americas Army Ops is free.. OpenGL.. and yeah, also free. www.americasarmy.com
(still not a test suite)
I don't know where you can get real cad quality test suites that will work. You might try installing and working with blender
or another free modeler as well.