Dev Blog: Bringing DirectX 12 to Rise of the Tomb Raider

Jurjen Katsman, Studio Head at Nixxes Software

[Our developer blogs lift the curtain on the creation of Lara’s first tomb raiding expedition, and the technology we use to constantly improve it. Following the release of Rise of the Tomb Raider for PC, the title will be one of the first in the industry to integrate DirectX 12 support, allowing fans with older PCs or newer rigs to run at higher framerates and higher graphical settings. Nixxes Studio Head Jurjen Katsman dives deep into the new technology below.]

Pushing the boundaries of technology on PC has always been a passion of the development team at Nixxes, and Crystal Dynamics and Square Enix have been great partners for us in doing so. One of the challenges with PC development is guaranteeing players on as many different PC configurations as possible can have a great experience. For us this means ensuring that users with older PCs can still get a great gameplay experience, but also that users with higher-end machines can get the most out of their hardware, including the highest quality visuals, frame-rate, and other technical enhancements.

One thing we are very excited about to help us further realize those goals is the new DirectX 12 graphics API that is available on Windows 10. In the patch released today on Steam – and coming soon to the Windows 10 Store – we will be adding DirectX 12 support to Rise of the Tomb Raider.

At Nixxes we have a long history of working with consoles as well, and one of the large differences between developing for consoles and developing for PCs is the level of access to the hardware available to us. We can leverage every single hardware feature and every bit of CPU power available in the most efficient way possible. With DirectX 12 we are taking a massive step forwards for bringing a lot of that flexibility to the PC as well. For Rise of the Tomb Raider the largest gain DirectX 12 will give us is the ability to spread our CPU rendering work over all CPU cores, without introducing additional overhead. This is especially important on 8-core CPUs like Intel i7’s or many AMD FX processors.

Let me explain how this helps the performance of your game. When using DirectX 11, in situations where the game is under heavy load – for example in the larger hubs of the game – the individual cores may not be able to feed a fast GPU like an NVIDIA GTX 980 or even NVIDIA GTX 970 quick enough. This means the game may not hit the desired frame-rate, requiring you to turn down settings that impact CPU performance. Even though the game can use all your CPU cores, the majority of the DirectX 11 related work is all happening on a single core. With DirectX 12 a lot of the work is spread over many cores, and the framerate of the game will run at can be much higher for the same settings. Check out the picture below for a visual example of how the CPU work is distributed:

As an example to illustrate the point, below is a screenshot of a scene in the game running on an Intel i7-2600 processor with 1333Mhz memory, paired with a GTX 970. Using DirectX 11 at High Settings we would only get 46 fps.

Now look at the same location the new DirectX 12 implementation, we can lift it up to 60!

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!

[Rise of the Tomb Raider is available now on Xbox One, Xbox 360, and PC. Secure your copy at BuyROTTR.com]