stiganator, what you said cannot be done, and is not how it is done.
the video and processor systems are pretty much independent from each other. and the processors do not control the video cards.
what having 2 processors mean is having the ability to spill over processor cycles onto a second processor instead of waiting for the processor to finish doing certain tasks. or sharing tasks between the processors.
having 2 video cards, via the windows multi-display adapter, means having more desktop space to work with, as opposed to one display adapter at a high resolution.