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What is DirectX, and why is it important for PC games?

DirectX is the secret sauce that allows most of the best PC games to run. It solves a problem for developers by offering a standardized solution to communicate instructions to your graphics card, and it’s a cornerstone of the best graphics cards you can buy right now.

We’ll run you through what DirectX is, why DirectX 12 Ultimate is important, and how you can find what DirectX version is installed on your PC.

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What is DirectX?

DirectX 12 Ultimate logo.

DirectX is an application programming interface (API) developed by Microsoft for Windows and Xbox. A graphics API is a middleman that facilitates sending instructions from software to the hardware inside your PC. In the early days of computers, instructions went straight to the hardware. However, as games have become more complicated and security measures more direct, APIs have been the backbone of telling your GPU what to do.

In years past, game developers would need to write drivers for multiple graphics cards. APIs like DirectX are standardized, which allows your AMD or Nvidia drivers to do everything regardless of what graphics card you have. Graphics APIs also enable features like hardware-accelerated ray tracing, and they can boost performance through various optimizations.

DirectX isn’t the only graphics API, but it’s the main one you’ll encounter. It’s exclusive to Windows, however, while open-source APIs like Vulkan provide cross-platform support.

DirectX 12 Ultimate explained

DirectX ray tracing in Battlefield V.

The most recent version of DirectX is DirectX 12 Ultimate, which is available on Windows 10, Windows 11, and Xbox Series X/S. Microsoft describes it as “additive” to DirectX 12, bringing features like ray tracing and variable rate shading to Windows and Xbox consoles.

Here are all of the additional features in DirectX 12 Ultimate:

  • DirectX ray tracing (DXR): An early version of ray tracing introduced in games like Fortnite and Battlefield V. Most titles that support ray tracing do so through DXR (though Vulkan has its own ray tracing support, as well).
  • Variable rate shading (VRS): Allows the GPU to allocate different amounts of power to different areas in a frame. The idea is to boost performance by focusing on the most important areas of a scene, which saves resources in less demanding areas.
  • Mesh shaders: Mesh shaders are a complex topic, but they essentially combine multiple shader steps into a single process. This avoids passing between your CPU and RAM when drawing meshes, which improves performance.
  • Sampler feedback: Modern games stream assets into the game world, and the game is forced to predict what to stream next based on what the player is doing. Sampler feedback feeds samples of what could happen without actually executing the instruction, allowing games to make better decisions about what assets to stream in.

Although DirectX 12 Ultimate has many new features, you don’t need to worry about them. They’re mainly for developers to optimize games beyond what they could do in DirectX 12 or DirectX 11. The most important addition is DXR, which enables ray tracing not only on PC but on the Xbox Series X, as well.

How to install and update DirectX

DXdiag menu in Windows 11.

You can’t install DirectX directly. It comes with Windows, and you can only update it with Windows. If you see an offer to install DirectX online, avoid it at all costs. Microsoft doesn’t make any installers available.

Installing and updating DirectX involves performing a Windows Update. Read our full guide on how to install Windows 11 if you’re starting from scratch. Before updating DirectX, you need to figure out your DirectX version, which you can do by following these steps:

  • Right-click on the Windows icon in the Start bar and select Run. 
  • Type “dxdiag” into the box and select OK. 
  • Check for DirectX version under the System tab.

As long as you’ve kept Windows up to date, you should have the latest version. If you don’t, you can force Windows to check for new updates with the following steps:

  • Use Windows Key+S to pull up the search box.
  • Search for Check for updates and select it.
  • Use the Check for updates button to search for new updates.
  • Click Install now. 

Which version of DirectX should you use?

A player stands next to their mushroom companion in Tiny Tina's Wonderlands.

DirectX is backward compatible, so it’s usually best to use the most recent version that the game you want to play supports. Most games only support one version, but there are a handful of titles that straddle the line between versions like Control, Civilization VI, and Tiny Tina’s Wonderlands. 

More recent versions of DirectX bring better features and opportunities for developers to optimize performance. If you want to dig in deep on those optimizations, make sure to read our comparison between DirectX 11 and DirectX 12.

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