Sry, I don't understand your reply. There are only those 3 options in the Display Resolution setting that I mentioned before. It doesn't matter what I choose, the performance remains the same.
My phone is not rooted. It has the stock Android 4.1.2 version. Where is that built in hardware scaler (maybe resolution changer?) setting?
My phone is not rooted. It has the stock Android 4.1.2 version. Where is that built in hardware scaler (maybe resolution changer?) setting?

