I've got a laptop Dell Inspiron 15 7548 (core i7, 16GB, R7 M265). I have Ubuntu installed on it. The laptop has descent GPU which I would like to use and I have installed and reinstalled the GPU drivers multiple times and Ubuntu detects the GPU properly. However the performance is catastrophic... 720p youtube video runs at 1-2fps. The integrated GPU works much better but it is too week to run anything properly (the laptop has 4k display). Really disappointing... Does anyone else have similar problem or may know a solution to this? Thanks!
The driver I am using is from here:Desktop