Several graphicscards per sli or crossfire are completely managed by the driver,as far as I know. DirectX or OpenGL are implemented by the drivers and do just offer function to say what to render. It is different with several CPUs. The programmer has to tell the programme where to execute which function on his own. And has to take care of all the difficulties. As far as I know A7 isn't designed to use several CPUs and thus they won't speed things up. But you can use more than one CPU with Lite-C if you want. That way you could for example speed up a complex AI or an external physicsengine could benefit from it.