If like me you don’t want/need 3D graphics for gaming when using Debian Linux on your Ativ Book 8 you can turn off the AMD Radeon HD 8700M component. Reason for doing this is that if it’s left running (in Debian Jessie) it will suck your battery dry (probably an exaggeration, but it definitely reduces battery life considerably). By disabling it just the IntelHD GPU is used and battery life is great.
Show the cards enabled
lspci -nn | grep VGA
Edit your grub boot config
sudo nano /etc/default/grub
Make your GRUB_CMDLINE_LINUX_DEFAULT line the same as below:
GRUB_CMDLINE_LINUX_DEFAULT="quiet acpi_backlight=vendor acpiphp.disable=1"
Run the following:
sudo update-grub
reboot
Check it’s worked
lspci -nn | grep VGA
If it has it will look like:
00:02.0 VGA compatible controller [0300]: Intel Corporation 3rd Gen Core processor Graphics Controller [8086:0166] (rev 09)