If you've been playing Rainbow Six Siege on PC, you may have heard a lot about the Vulkan API lately: along with Siege's latest balancing patch, there was a public test of a version that runs on Vulkan instead of DirectX 11. But what exactly is Vulkan and what are the potential benefits of using it?

Vulkan is a graphics API, which acts as an intermediary between the game and the graphics card. Ubisoft is pursuing Vulkan because it offers better performance than DirectX 11, the current API for games. In most hardware setups, "Siege" should run a little smoother with Vulkan.

That's cool, but the Vulkan version of "Siege" has a feature you should definitely know about: dynamic render scaling. This is a new setting exclusive to the Vulkan version that allows players to dynamically scale the rendering resolution to set a target fps that should always be reached. The new slider is located under the Graphics menu, but will not work unless anti-aliasing is set to one of the T-AA settings.

If you have hardware that can realistically achieve the target fps, it will actually work. With the target fps set to 144, the game has never run so smoothly; rendering at 1080p with an RTX2060 and a Ryzen 5 2600, I've averaged 135-144 fps. Maybe my eyes aren't as sensitive to graphical changes, but I haven't noticed a drop in resolution. However, there are a few quirks early on. I noticed that every time I restart the game I have to reset the target fps. A bit annoying, but more than worth it.

Launching Siege with Vulkan requires no special adjustments or time; if you are playing on Steam, launching the game on Steam will pop up an additional window asking whether you want to launch with the standard or Vulkan version. from Uplay If you are launching the game, there should be a similar drop-down option when you press the play button.

Don't panic. There is a problem with the current build and if you have the Starter Edition of Siege, which was discontinued in 2019, it does not give players the option to launch in Vulkan. If you do, Reddit user Andersson799 has you covered. They have posted a fix that works by changing the name of the Siege executable. Try this at your own risk or wait until Ubisoft fixes the problem.

Ubisoft is excited about Vulkan because it fundamentally reduces the burden on the PC; as Ubi's post explains, Vulkan is close to "bare metal" PC hardware and thus uses less CPU. Since Vulkan is much newer than Siege's 10-year-old DirectX 11, it also supports the latest features that help further optimize CPU workloads. Adaptive render scaling is one of these perks. Vulkan is not the only modern API that supports these features, but Ubi chose Vulkan after internal performance testing." We also evaluated DirectX 12, but our internal tests show that Vulkan has better CPU performance."

Vulkan's other main advantage is its broad compatibility with other platforms: it is available for Windows, OSX, Android, and Linux. This makes it an attractive option for porting games across platforms, and Siege may be looking at new consoles and cloud gaming. For example, Google Stadia needs Linux support.