Thanks for your help. 3D programs use OpenGl extensively, and my PC only crashes those programs. I'm not having crashes in programs that don't use it. As an example, Cinebench has two tests, one for CPU rendering and one for OpenGL. I can run the CPU rendering test without issue. As soon as I try the OpenGL test, the program crashes.
I ran the Windows DirectX Diagnostic Tool. It found no problems with my GPUs, so I'm assuming that isn't the issue, unless there are additional tests I can run to test that.
The programs crashing are only animation and 3D programs, which use OpenGL for viewport support. These include Cinema 4d, Akeytsu (animation program), Toon Boom (2d animation program, which uses OpenGL for anti-aliasing), Cinebench (for testing OpenGL), FurMark (tests OpenGL), and OpenGL Extension Viewer (OpenGL testing). I use a lot of non-OpenGL programs on a daily basis for hours on end without any crashes, such as InDesign, Illustrator, and Photoshop. I believe Photoshop may use OpenGL when used for 3D models, but that isn't a function I ever work in.
I've tested each video card separately in different slots, but it doesn't affect the issue at all.
I haven't performed any overclocking.