I know that nobody likes duplicate questions, but I haven't found my answer on any of the other questions with this topic.
I built a computer with a GeForce GTX 750 GPU (made by Gigabyte). It supposedly has 512 CUDA cores. I followed this tutorial, (which enabled the Nvidia proprietary drivers) and was able to enable dual monitors and all the desktop graphics that are needed. Unfortunetly, the GPU processing option still doesn't show up in Blender. I've tried installing nvidia-cuda-toolkit, and that didn't make a difference. I also tried to update my drivers from nvidia-346 to nvidia-349, and this had no apparent effect either. What can I do to enable GPU rendering? (I've tried both blender installed and just downloaded from the site).