I'm new to some of the Adobe products, particularly After Effects CC. Upon opening it for the first time it informed me I needed CUDA 5.0 or greater with my NVIDIA graphics card. I have a 15" MacBook Pro with NVIDIA GeForce GT 750M. I'm not sure what downloading and installing CUDA 6 will do and if it's necessary. To me it seems strange that the latest version of After Effects CC is immediately asking for additional things to help it run. Can someone give me the dummies version, please?
That message is saying that you must have CUDA 5.0 or higher (which you do) and one of a specific set of GPUs (which you don't) to make use of one specific feature, the ray-traced 3D renderer.
For details of this feature and how it uses the GPU, see this page:
However, you should not concern yourself with this feature. The ray-traced 3D renderer is an obsolete feature that has been superseded by several better ways of doing 3D in After Effects, including using Cinema 4D (which is included with After Effects now): http://blogs.adobe.com/aftereffects/2013/04/details-of-cinema-4d-integration-with-after-ef fects.html
All that said, if you want to force After Effects to use your unsupported GPU for the ray-traced 3D renderer, you can do so as described here: