See this page for details about how After Effects uses the GPU:
Note that the card that you mention is not one that will be used by After Effects for GPU acceleration of the ray-traced 3D renderer.
"Note: To use Kepler-class graphics cards (such as the GTX 680) for the GPU-accelerated ray-traced 3D renderer, you need to install the After Effects CS6 (11.0.1) or (11.0.2) update."
Doesn't that means it should work then?!
No. Each card must be individually tested before it is added to the list. The line that you excerpted is saying that in order to use the specific Kepler cards that were added to the list, you must install those updates; it is not saying that every Kepler card was added to the list.
If you want that card to be considered, you can submit a feature request:
Thanks a lot for the very fast answers =)