Mr SMK :
Will it be more efficient than CPU based encoding ?
That largely depends on how you are measuring efficiency, but I'd say marginally at best. Handbrake is just a GUI for the command line encoder x264. x264 is a software encoder that can offload a small component of its workload to the GPU for a small overall performance improvement. The vast majority of the encoding will still be done on the CPU. If you want "proper" GPU acceleration you'll need to look elsewhere. There is also the option to use Intel's Quick Sync or Nvidia's NVENC, which are neither GPU nor CPU encoders, but rather dedicated hardware that is built specifically for encoding (and decoding in the case of Quick Sync) video. They are fast, but you'll get arguably...