Not necessarily. This will all depend on your specific configuration. Many times it will hinge on a "first come, first served" principle, meaning if the nVidia card is not the system's primary graphics adapter, its functions may not be available to programs or not be detected properly. Likewise, if the AMD card is the primary card any program that uses hardware acceleration may simply latch onto that, even AE's normal OpenGL functions, or on the opposite side this may cause resource conflicts so no hardware acceleration is avialable at all. Really depends, but this is too specific to answer on a forum. One would have to have ful laccess to your system's configuration down to knowing which PCI slots/ buses your cards occupy.