This Steam Community Group Announcement has details on a new patch for Rise of the Tomb Raider that adds DirectX 12 support to the Windows edition of the adventure game (a patch for those who got the game through the Windows 10 store will follow). Square Enix says they "expect this patch to be an improvement for everyone," but they offer the ability to revert to the previous version for anyone with problems. They point to this blog post for more details, as PC developer Nixxes Software explains some of the advantages DirectX 12 brings. Here's a bit:

The above advantage we feel is the most important one for Rise of the Tomb Raider, but there are many more advantages that make us excited about DirectX 12. Another big feature, which we are also using on Xbox One, is asynchronous compute. This allows us to re-use GPU power that would otherwise go to waste, and do multiple tasks in parallel. And there is a never before seen level of control over NVIDIA SLI and AMD CrossFireX configurations, which means that as a developer we can take full control over those systems and ensure users get a great experience with them.

Being one of the first game titles out there using DirectX 12 there are still many more optimizations to make and DirectX 11 is available for the most predictable and proven experience. However, as seen above there are large gains to be found already, and we encourage you to check out DirectX 12 for yourself in our latest patch!