I managed to get fglrx driver working on my kali linux:
the problem is the fglrx driver falls back to NON direct rendering which slows down the gpu operations.

1) installed fglrx from the kali linux default repositories my cat /etc/apt/sources.list (no thing added)
Code:
## Regular repositories
deb http://http.kali.org/kali kali main non-free contrib
deb http://security.kali.org/kali-security kali/updates main contrib non-free

## Source repositories
deb-src http://http.kali.org/kali kali main non-free contrib
deb-src http://security.kali.org/kali-security kali/updates main contrib non-free

## Bleeding Edge repositories
deb http://repo.kali.org/kali kali-bleeding-edge main
deb-src http://repo.kali.org/kali kali-bleeding-edge main
2) cat /etc/X11/xorg.conf.d/20-fglrx.conf (i have no xorg.conf file)
Code:
Section "Device"
	Identifier "My GPU"
	Driver "fglrx"
EndSection
3) glxinfo | grep -i render
direct rendering: No (If you want to find out why, try setting LIBGL_DEBUG=verbose)
OpenGL renderer string: AMD Mobility Radeon HD 5000 Series

4) after setting LIBGL_DEBUG=verbose
libGL: screen 0 does not appear to be DRI2 capable
libGL: OpenDriver: trying /usr/lib/x86_64-linux-gnu/dri/tls/swrast_dri.so
libGL: OpenDriver: trying /usr/lib/x86_64-linux-gnu/dri/swrast_dri.so
libGL error: reverting to indirect rendering

please ask me for any extra info about my notebook that helps in diagnosing.
thank you for your time.
glxinfo-output.txt