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[Issue Report]: AMD Dual graphics technology

Question asked by mattyy1hp on Jan 22, 2013
Latest reply on Feb 26, 2013 by pqyptixa

I have a laptop with the AMD Dual Graphics technology.

This technology contains AMD APU (Accelerated procesor) + AMD GPU (dedicated GPU) to work together in crossfire.

I know that this technology is designed for Windows in DirectX 10 and DirectX 11. But there are also a lot of issues with this combination.

I don't know, how to describe some issues, so I attached a screenshots.

 

My specs:

CPU/APU: AMD A6-3400M with AMD Radeon HD 6520G APU

GPU: AMD Radeon HD 6470M

OS: Linux Mint 13 'Maya' 64bit

Kernel: 3.6.5

Drivers:  AMD Catalyst Linux proprietary driver 13.1

Configuration: "amdconfig --initial" and "amdconfig --initial --adapter=all" - it's same

 

Crossfire don't work. But Catalyst let me at least to switch between both graphics cards.

This issues I didn't had on my previous laptop with only one AMD GPU, so, I'm assume that are caused by AMD Dual Graphics.

I tried: Cinnamon, Cinnamon 2D, MATE, Gnome 3, Xfce, Unity (on Ubuntu) - no difference

 

When I'm on 6520G APU:

 

1/ Taking a screenshots on Cinnamon

- For example: If I have Firefox minimalized in the taskbar and I do a screenshot of my desktop, I see Firefox on the screenshoot

 

2/ AMD Catalyst don't show the dedicated GPU

- I don't know, if this is a bug. I can post a screenshot, because I can't take screenshot on this graphics card - look at my "issue 1"

 

3/ vSync don't work

- There is a invisible line on the top of a screen where the vSync don't work. Look at screenshot 6520g_vsync.png.

- of course, I have "wait for vertical sync" - "always on"

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When I'm on 6470M dedicated GPU:

 

1/ vSync don't work

- There is a invisible line on the top of a screen where the vSync don't work. Look at screenshot "6470m_vsync.png"

- The top part is rendered slower than the bottom one.

- Much worse than same issue on APU.

- I have "wait for vertical sync" on "always on"

- I can't capture it on screenshot, only on a photo, look at "vsync.jpg".

- It's much worse in movies and games

 

2/ AMD Catalyst shows both graphics cards

- I don't know, if this is a bug. On APU, I don't see this GPU (look at my "issue 2" on APU) and screenshot "both_gpus_on_6470m.png"

 

3/ AMD Vari-Bright don't work

- Vari-bright is always set to "maximize battery life". If I change it to any other value and confirm it by "apply", it will return back to "maximize battery life"

 

4/ Can't start TF2

- This is not happen on 6520G APU

- TF2 hangs on "loading ..." screen after Valve logo

- I waited more than 30 minutes, it never starts

- https://github.com/ValveSoftware/steam-for-linux/issues/407

 

5/ Display settings shows APU, no GPU

- I have activated the dedicated GPU 6470M, but in AMD catalyst, it shows AMD 6520G APU, look at screenshot "displays.png"

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