internal or ext sd, which is efficient?

I use my s3 mainly for music and camera video, the size of the internal memory is more than enough, so which is more efficient in terms of use and battery?, just use the internal memory alone with faster read and write then remove then sdcard? Or just keep the sd? Isnt it will just consume more power since you are running both reader especially when listening to music for long period? The only advantage of sd is you can remove it along with your files if the phone broke down, but since i backup my files most of time i dont think its an issue, cant decide, give me opinions pls