Hello my gpu is [AMD] RS780/RS880 i want get resolution 1920x1080 but i cannot . What to do to set that up ??

xrandr -q
xrandr: Failed to get size of gamma for output default
Screen 0: minimum 640 x 400, current 1280 x 1024, maximum 1280 x 1024
default connected 1280x1024+0+0 0mm x 0mm
1280x1024 0.00*
1024x768 0.00
800x600 0.00
640x480 0.00
720x400 0.00
1920x1080_75.00 (0x62) 220.640MHz
h: width 1920 start 2056 end 2264 total 2608 skew 0 clock 84.60KHz
v: height 1080 start 1081 end 1084 total 1128 clock 75.00Hz

Not enough information. What distro? Most likely you haven't installed firmware required for your AMD GPU. Normally, automagic will provide your display's native resolution. Pastebin the file /var/log/Xorg.0.log and paste here using code tags, its result and output from command inxi -SGaz.

/lib/firmware/radeon must exist and filled with proper files. More information is required for more detailed help.

See the OP's other thread before offering assistance.

1 members found this post helpful.