HAL vs. REF Devices

https://docs.microsoft.com/en-us/windows/win32/direct3d9/device-types

Direct3D supports an additional device type called a reference device or "reference rasterizer".

- This device is intended to be used for debugging purposes and is therefore only available on machines where the DirectX SDK has been installed.

- Because these features are implemented for accuracy rather than speed and are implemented in software, the results are not very fast.

D3D_DRIVER_TYPE enumeration: D3D_DRIVER_TYPE_REFERENCE

https://docs.microsoft.com/en-us/windows/win32/api/d3dcommon/ne-d3dcommon-d3d_driver_type

A reference driver, which is a software implementation that supports every Direct3D feature.

This driver may be referred to as a REF driver, a reference driver, or a "reference rasterizer".

How To: Create a Reference Device

https://docs.microsoft.com/en-us/windows/win32/direct3d11/overviews-direct3d-11-devices-create-ref