Turn off Vsync (Radeon) and Create Xorg. Conf

I want to turn off vsync because I want to play games at more than 60 fps. To turn off vsync I have tried to follow this link on the arch Wiki. I created the file .drirc and copy and pasted it. This didn't work unfortunately.

So I tried to create xorg.conf with # X :2 configure. This command gives me an error and it terminates.

The error I receive is:

no devices to configure. Configuration failed.

I then tried to use tty1:

# service lightdm stop
# X -configure
# service lightdm start

But I received the same error message when I tried to create the config.

As a last resort I tried to use fglrx but I got the same message again. So I don't know what to do anymore. I am using Ubuntu 15.10 and my Graphics card is a Radeon HD 6870.

Any help is very appreciated.