Asus eeePC: AMD-C60 64-bit, 1GB-RAM:
I had to install some extra firmware for OpenGL, DRI and VAAPI (video decoding)
sudo apt install firmware-linux-free firmware-amd-graphics avinfo
Now plays high-bitrate H264 (AVC)/DTS full HD Video fluently 
(without VAAPI it would absolutely be a slideshow)
I also discovered that Gamma Linux does not have a form of NTP installed, so here some instructions to make it work:
# install the package
sudo apt update
sudo apt install systemd-timesyncd
# enable and start the service
sudo systemctl enable systemd-timesyncd
sudo systemctl start systemd-timesyncd
# enable NTP sync via timedatectl
sudo timedatectl set-ntp true
# check the sync status
timedatectl status
I pimped the desktop a bit:
thom@deimos:~$ free -h
total used free shared buff/cache available
Mem: 725Mi 253Mi 160Mi 852Ki 420Mi 471Mi
Swap: 7.7Gi 0B 7.7Gi
Gamma linux is a keeper 