剛剛看見了，wrap device && reference device
區別在這裡
https://msdn.microsoft.com/en-us/library/windows/desktop/ff476328(v=vs.85).aspx
D3D_DRIVER_TYPE_WARP
A WARP driver, which is a high-performance software rasterizer. The rasterizer supportsfeature levels 9_1 through level 10_1 with a high performance software implementation. For information about limitations creating a WARP device on certain feature levels, see Limitations Creating WARP and Reference Devices. For more information about using a WARP driver, see Windows Advanced Rasterization Platform (WARP) In-Depth Guide.
Windows Advanced Rasterization Platform 的縮寫
D3D_DRIVER_TYPE_REFERENCE
A reference driver, which is a software implementation that supports every Direct3D feature. A reference driver is designed for accuracy rather than speed and as a result is slow but accurate. The rasterizer portion of the driver does make use of special CPU instructions whenever it can, but it is not intended for retail applications; use it only for feature testing, demonstration of functionality, debugging, or verifying bugs in other drivers. The reference device for this driver is installed by the Windows SDK 8.0 or later and is intended only as a debug aid for development purposes. This driver may be referred to as a REF driver, a reference driver, or a reference rasterizer.