I have a HP Pavillion Laptop running Ubuntu 14.04 LTS. It has an AMD APU with integrated 8650G and a discrete AMD 8670M GPUs.
ajith@SoulCube:~$ uname -a
Linux SoulCube 3.13.0-34-generic #60-Ubuntu SMP Wed Aug 13 15:45:27 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux
ajith@SoulCube:~$ I am using the fglrx driver installed using the 'Additional Drivers' tool
I have read that the dual graphics will switch back and forth between the iGPU and the dGPU according to workload, but my laptop seems to be not doing that.
I had tried fglrxinfo but it only shows the iGPU and does not list the dGPU.
ajith@SoulCube:~$ fglrxinfo
display: :0 screen: 0
OpenGL vendor string: Advanced Micro Devices, Inc.
OpenGL renderer string: AMD Radeon HD 8650G
OpenGL version string: 4.3.12798 Compatibility Profile Context 13.35.1005
ajith@SoulCube:~$When I tried lspci | grep Radeon I got the following
ajith@SoulCube:~$ lspci | grep Radeon
00:01.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Richland [Radeon HD 8650G]
01:00.0 Display controller: Advanced Micro Devices, Inc. [AMD/ATI] Sun XT [Radeon HD 8670A/8670M/8690M]
ajith@SoulCube:~$ I am curious as to why the dGPU is listed as a Display Controller and not a VGA Compatible Controller. A lot of the Posts I have seen on the internet indicate that both of them should turn up as a VGA Compatible controller.
Can somebody help me understand the issue and help me switch permanently to using my discrete GPU. I have checked the BIOS for options pertaining to this but they are not available.
1 Answer
I did some more digging in google and found out at ubuntuforums that gpu-manager was causing the confusion.
I tried doing aticonfig --initial --adapter=1 to generate an xorg.conf file, but the file was getting replaced with an near empty file on reboot.
On reboot my system will default to the integrated GPU. I guess its the driver making this decision on account of the xorg.conf file being incomplete.
I stumbled upon a bug report at which helped me solve the problem (temporarily atleast).
The temporary solution in the bug report was to comment out the start on lines at the beginning of the file /etc/init/gpu-manager.conf which should prevent the gpu-manager being started when lightdm started and replaced my xorg.conf file.
I have to read up on these to get a more concrete idea.
