Emulator

Game Name?
All games.

Game ID?
All games.

What's the problem? Describe what went wrong in few words.
Anisotropic Filtering is incorrectly configured in the D3D backend, in the GUI and in gfx_dx11.ini.

The options in the GUI are x1, x2, x4, x8 and x16, which are represented by the option "MaxAnisotropy" in the ini file, with values 0, 1, 2, 3, or 4.
Switching between them ingame shows that the x2 and x8 options don't work as expected. They look the same as the previous step. So the only working ones are x1, x4 and x16.

The true problem is that I think those values are truly x1, x2 and x4 ingame. How did I find out? Putting "MaxAnisotropy = 16" in the ini file. It looks better than the x16 option in the GUI. Switching to windowed mode and opening the graphics configuration shows that the AF option has its value in blank (obvious because 16 in the ini doesn't correspond with anything in the GUI). Switching to AFx16 shows an immediate decrease of AF quality in the game.

In the Dolphin profile of the Nvidia drivers AF isn't forced, so nothing is interfering.

What did you expect to happen instead?
I expected AF to work correctly, as in the OpenGL backend. In OpenGL, all AF steps work and the x16 option looks the same as "MaxAnisotropy = 16" forced in the D3D ini.

What steps will reproduce the problem?

1. Use AFx16 in the D3D backend.
2. Look at how the x2 and x8 options don't work as they should.
3. Change "MaxAnisotropy" to 16 in "gfx_dx11.ini".
4. See how it looks better than AFx16 in the GUI, and switching to AFx16 reduces quality.

Dolphin 3.5 and 3.5-367 are old versions of Dolphin that have
known issues and bugs, so don't report issues about them and test the
latest Dolphin version first.
Which versions of Dolphin did you test on?
Latest development build at the moment: 4.0-5815. It also happens in 4.0-4478.

Does using an older version of Dolphin solve your issue? If yes, which
versions of Dolphin used to work?
The oldest one I tried this is 4.0-4478, which still has the problem. I don't know since when this issue exists.

What are your PC specifications? (including, but not limited to: Operating
System, CPU and GPU)
CPU: Intel Core i5 4670k @ 4.4GHz
GPU: Nvidia GTX 760
RAM: G.SKILL RIPJAWS X @ 1866MHz CL8
OS: Windows 7 Ultimate x64

Is there any other relevant information? (e.g. logs, screenshots,
configuration files)
Here are 4 screenshots:

Metroid Prime with AFx16 in GUI: http://i.cubeupload.com/932I5R.png
Metroid Prime with MaxAnisotropy=16 in ini: http://i.cubeupload.com/hF7jrF.png

F-Zero GX with AFx16 in GUI: http://i.cubeupload.com/kAJKoL.png
F-Zero GX with MaxAnisotropy=16 in ini: http://i.cubeupload.com/qyDOyw.png