Blog/post/installing-ati-radeon-hd-6870-on-a-2560x1080-monitor-on-ubuntu-1004-focal

=Hardware info=

lshw -c video

*-display description: VGA compatible controller product: Barts XT [Radeon HD 6870] vendor: Advanced Micro Devices, Inc. [AMD/ATI] physical id: 0 bus info: pci@0000:02:00.0 version: 00 width: 64 bits clock: 33MHz capabilities: pm pciexpress msi vga_controller bus_master cap_list rom configuration: driver=radeon latency=0 resources: irq:37 memory:d0000000-dfffffff memory:fbbc0000-fbbdffff ioport:b000(size=256) memory:c0000-dffff

lspci -k | grep -EA2 'VGA|3D' 02:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Barts XT [Radeon HD 6870] Subsystem: Advanced Micro Devices, Inc. [AMD/ATI] Barts XT [Radeon HD 6870] Kernel driver in use: radeon

linux-hardware: AMD Radeon HD 6870

=Removing old drivers (for nvidia card)=

sudo apt-get remove --purge '^nvidia-.*'

sudo apt-get install --reinstall xserver-xorg-video-intel libgl1-mesa-glx libgl1-mesa-dri xserver-xorg-core

sudo dpkg-reconfigure xserver-xorg

sudo mv /etc/X11/xorg.conf /etc/X11/xorg.conf.bak

=Video Drivers=


 * Use "radeon" driver
 * "amdgpu" incompatable (only newer cards)
 * "amdgpu-pro" incompatable (only newer cards)
 * "frglx", obsolete, unmaintained since Ubuntu 12 or 13 or so

=Cables=


 * DVI(Single Link) doesnt support greater than 1920x1080(FHD)
 * DVI(Dual Link) might work, i didn't have one
 * HDMI didn't support greater than 1920x1080(FHD), I guess the graphics card uses an older version of HDMI
 * DisplayPort: I had to use a mini-Display Port(miniDP) to Display Port(DP) cable to get the full resolution

=Check for Errors=

dmesg | egrep 'drm|radeon'

=References=

http://help.ubuntu.com/community/RadeonDriver