Rise of the Tomb Raider has had a steady stream of updates since it hit Steam in February, with the fifth patch released just yesterday. However, along with the expected packet of fixes and tweaks, it introduced DirectX 12 support for the rather gorgeous title.
Microsoft stated a while back that games featuring DirectX / Direct3D 12 support would start trickling out from the end of 2015 onwards — and it wasn't wrong. Rise of the Tomb Raider is among the first off the rink and according to the update notes, should improve performance on systems with hardware and OS support:
Added support for DirectX 12 - DirectX 12 is a new advanced graphics API that on the right hardware can offer far better performance. - For the best DX12 performance and stability please install the latest drivers for your GPU. - For NVIDIA: http://www.nvidia.com/download/driverResults.aspx/99512/en-us - For AMD: http://support.amd.com/en-us/kb-articles/Pages/AMD_Radeon_Software_Crimson_Edition_16.3.aspx
Adds NVIDIA VXAO Ambient Occlusion technology. This is the world's most advanced real-time AO solution, specifically developed for NVIDIA Maxwell hardware. (Steam Only) Added a new benchmark feature to allow easy comparison of performance on different systems, as well as at different graphics settings. Fixed some HBAO+ and other Ambient Occlusion issues. Fixed motion blur problems in Stereoscopic 3D mode. A variety of other smaller optimizations, bug-fixes, and tweaks.
For those after more technical details, there's a developer post available just for you. Essentially, DirectX 12 allows the game's rendering engine to better utilise CPU resources, which should equate to a framerate boost in situations where the processor can't keep up with the GPU demands.
In one test (shown in the post), an Intel i7-2600 paired with an NVIDIA GTX 970 went from 46 frames per sound to 60.
Of course, there are caveats. You should expect your experience to differ based on your hardware configuration and Nixxes Software, the studio handling the implementation, is still experimenting, tweaking and optimising the pipeline.