The following image formats are supported by the DX11 shader in Viewport 2.0:
For DX11: See the June 2010 version of the Microsoft DirectX SDK documentation for list of supported formats.
The File texture node maps floating point values to values between 0-1 for its swatch display and DG evaluation. However, Viewport 2.0 may directly support floating point values without tone mapping. For .exr and .dds files connected to File texture nodes that are mapped to the attributes of the DirectX 11 Shader, floating point bit depth is supported in the viewport.
Only fixed point bit depth is supported for tif files. Use exr files instead for floating point displacement maps.