I use System.Windows.Media.RenderCapability.Tier to show the current render mode within a diagnostics panel of my app. If I force the app (3.5sp1) to change the render-mode through the following code

HwndSource hwndSource = PresentationSource.FromVisual(visual) as System.Windows.Interop.HwndSource;
HwndTarget hwndTarget = hwndSource.CompositionTarget;
hwndTarget.RenderMode = renderMode;

neither System.Windows.Media.RenderCapability.TierChanged fires, nor has the System.Windows.Media.RenderCapability.Tier property changed. However the changes are applied to the app. If I look with Perforator, the render mode has been changed to the desired mode.

Although I’ve found at many locations that System.Windows.Media.RenderCapability.Tier can be used to detect the current render state (also msdn, see this), it seems, System.Windows.Media.RenderCapability only gives information about the capabilities and not about the current mode. That makes also sense if I look at the name of the class.

Is there another source to know how an actual wpf-content is rendered or am I doing something wrong?