I'm using DirectX 11 with the feature level 9_3 even though my computer could run 11_0, but I want to support older hardware as well.
I'm using CheckMultisampleQualityLevels to check whether multi sampling with the given samplecount is supported or not. However it returns 1 for quality with 4samples. And with 8samples it returns 0 (so its not supported). With feature level 11_0 CheckMultisampleQualityLevels returns 1 for 8samples. I'm using a AMD/ATI Radeon HD5830. In the most DirectX9 games I can still use 8x antialiasing. So why is it not supported in DX11 with a lower feature level.
Another point is it seems like 4samples doesnt really affect the output:

With mutlisampling disabled the result is the same. I'm sure that I configurated ms correctly.. even in the Depthbuffer.
Whether I enable AntialiasedLineEnable in the RasterizerDesc or not the output is still the same.
I searched in MSDN but I couldn't find any more information about multisampling.
EDIT: The blacklines in the picture are outlines made in the pixelshader