I know Cycles will limit the available VRAM to that of the GPU with the least VRAM if multiple GPUs are used for rendering at the same time, but what happens if only one of the GPUs is used for rendering?
For example, I currently have a GTX 560 ti in my system with only 1gb of VRAM. If I added a GTX 670 with 4gb of VRAM and ONLY used the GTX 670 for GPU rendering, would the amount of available VRAM still be limited to the 1gb offered by the GTX 560 ti even though it is not being used?
More specifically I am planning on adding a GTX 670 to my workstation rig alongside a Firepro W5000 that has 2gb of VRAM. Blender can’t use the Firepro for GPU rendering so might it still limit the VRAM of the GTX 670?