I am in need of a preferably free, but it doesn't have to be, video converter application that utilizes my newer GTX 760 via CUDA GPU acceleration. I am currently using Free CUDA Converter version 6.1. Also there are settings I cannot fully interpret so if anyone knows what the settings should be for "Maximum Simultaneous Processes" and "Maximum Simultaneous Running Processes" please let me know. They are currently at 16 and 8 respectively. I OC my i7-3770K to 4.2Ghz and GPU to 1225Mhz fyi. The GTX 760 has 1152 CUDA cores. Thanks for your help/suggestions, I hope to get some feedback.
Handbrake, as was mentioned by amdfangirl, is a good choice. Another one to consider is MPEG Streamclip.
For using CUDA MediaCoder was suggested in this thread: http://www.tomshardware.com/forum/242083-49-best-cuda-v...
Any Video Converter claims to make conversion rates faster with the use of CUDA: http://www.any-video-converter.com/speedup-conversion-w...
The GPU may benefit more with rendering than encoding which may be best left to the CPU. After much reading it appears as though you will get better quality video encodes using the CPU vs. the GPU.
As far a file size goes it depends more on the container than the GPU (CUDA).
Basically, from much reading on the topic, you trade quality for speed when using a CUDA enabled encoder.