Feral Interactive, a company that brings windows games to Mac and Linux, has implemented its magic on Square Unix's Shadow of the Tomb Raider and has it working in Ubuntu via the Vulkan API. YouTuber Penguin Recordings has compared performance results for both the Ubuntu and Windows 10 platforms side-by-side. The results are quite interesting.
Because Linux cannot support any type of DirectX API, as it's Microsoft-only, Feral Interactive has to use the Vulkan API to actively translate DX11 and/or DX12 calls to make them work on Linux. Fortunately, this method does work rather well, but performance will usually be slower than native DirectX due to the translation process.
Spec-wise, Penguin uses a Ryzen 9 3950X alongside a GeForce RTX 3090 with 32GB of RAM to run his tests.
Surprisingly, in DX12 mode for Shadow of the Tomb Raider, Feral's Linux version of the game could keep up with the Windows 10 platform quite well. Averaging between two to seven fps (and 10 fps above 100 fps) short of the Windows 10 version. The frame rate difference is so small it would be hard to notice without an fps counter visible.
Looking at the DX11 results, performance is very interesting. In non-AI intensive scenes, the DX11 API is a touch ahead of the Linux implementation in frame rate. But once you get into areas full of NPCs, the Linux platform can have up to a 40 fps lead with the Windows 10 DX11 mode absolutely tanking in performance. This is very bizarre and could legitimately be an issue with the Nvidia drivers or a bug somewhere in the game. This is more evident if you look at Pengiun's RTX 3090 utilization, which drops down to 60% when performance tanks, meanwhile the Linux platform maintains 100% utilization.
Overall, Feral's version of Shadow of the Tomb Raider is a solid performer. In DX12 mode, the performance is more than playable, and you should have a pleasant gaming experience. If you need to back down to DX11 for some reason, that mode is also good and far superior to native DX11 in Windows at this moment. You can grab the Linux compatible version of the game from Feral Interactive's online store.