Hi, I sent you an email but want to help everyone while answering you here.
CUDA drivers have nothing to do with anything but CUDA.
We have had large red text above product info with the message that drivers need to be installed first. Hopefully Apple will take a moment from designing new emoji bracelets and include current Nvidia Drivers in the OS. Meanwhile, you will need to install them yourself.
The first page of this thread has links but hasn't been updated with latest.
We have them here:
http://www.macvidcards.com/which-driver-should-i-install-for-my-new-gpu.html
Once you have installed the infamous "Security Update", then you will be able to use the latest driver from Nvidia.
Please note the large red letters where this is spelled out.
Please read ALL information on all links. You must install drivers for this card.
Anyone using any of the following cards needs to check in before updates:
GTX750
GTX750Ti
GTX780Ti
GTX Titan Black
GTX960
GTX970
GTX980
Due to Apple's insistence on retaining "retro" drivers from more than a year ago in OS X, none of the above cards are included in 10.10.2.
This is especially true for people with unflashed cards as they will see NOTHING, NADA, BLACK SCREEN without these. With EFI versions you will see computer boot but lock or boot-loop.
I will try to come on here and link to our Blog with future updates and best means of updating without causing a complete inability to use computer.
To find out which OS build you have, look in System Profile and click on the main "Software" bar to see "System Software Overview". The top line is "System Version" which will be expressed as "10.10.2 (14C1510)" This shows that you have latest OS and thus need the driver specified for that build.