In short, DirectX 12 Ultimate should make it a lot easier for developers to implement advanced graphics features in their upcoming games. Ray tracing (the fancy realistic light and shadow tech so beloved by Nvidia’s RTX cards at the moment) and variable rate shading (the ability to simulate certain chunks of the environment that don’t require so much detail as other parts of a scene to help boost performance) were already part of the original DirectX 12 protocol, but DirectX 12 Ultimate improves on these even further, which I’ll go into in a minute. It also adds two new features as well: support for mesh shaders and sampler feedback. Without getting too bogged down in the technical detail, mesh shaders effectively allow developers to program even more detailed and dynamic environments without making your GPU grind to a halt, while sampler feedback is all to do with shorter load times, less stuttering and higher visual fidelity by letting devs load in textures when they need to rather than all at once. Both the current crop of Nvidia RTX cards and the upcoming 4K Big Navi GPUs have been confirmed to support DirectX 12 Ultimate, but the good news is that games that end up making use of certain Ultimate features will still be compatible with older hardware, so you don’t need to worry about being locked out of any new PC games just because you haven’t upgraded your graphics card in a while. For those of you who do or are thinking about getting a compatible graphics card, though, here’s a brief overview of the improvements. Starting with ray tracing, also known as DirectX Ray tracing 1.1, these processes have all been streamlined and made more efficient, which will hopefully result in smaller performance dips when you switch it on in-game. AMD have also been working closely with Microsoft on the design of this update, and they’ve since showed off their very first ray tracing demo to show it off. Have a watch below. It’s chrome-o-matic.
Microsoft has also added support for an alternative form of ray tracing called inline ray tracing. This looks to be a slightly simpler form of the realistic light and shadow tech, or at least a simpler way of implementing it in real-time, giving developers another option of working it into their game. It can also be combined with the more traditional “dynamic” shader-based ray tracing to help manage the workload more efficiently. If you want to read more about it, you can peruse Microsoft’s dev blog on the subject. Microsoft didn’t go into too much detail on how they’ve improved their variable rate shading tech, all told, but it’s the addition of mesh shader support that’s a lot more interesting. Nvidia have a really good demo explaining what this is and what it means for games, which you can watch below. In short, it allows your GPU to render considerably more complex shapes and geometries on the fly without causing your GPU to buckle under the load. As for the long version, well, have a read of that there dev blog again, because it gets very technical very quickly.
As for sampler feedback, the benefit of this is very similar to what you get with variable rate shading - improving performance while reducing the amount of graphical overhead being done by your GPU. It allows for more efficient shading for objects that don’t change from frame-to-frame, and lets your GPU reuse the same colours that it calculated in previous frames. All in all, all the shiny new graphics features that Nvidia’s been banging on about for the last couple of years since the launch of their RTX cards are finally entering the mainstream, which will hopefully result in prettier looking games, and a more compelling reason to upgrade to a ray tracing-capable graphics card. Indeed, given Microsoft are largely introducing this new DirectX 12 standard in order to unify their Xbox Series X and PC strategies (the former of which, let’s not forget, is powered by an AMD Navi GPU), I’ll be intrigued to see whether AMD’s upcoming “Big Navi” GPUs end up utilising the technology more efficiently than Nvidia’s existing RTX cards. Nvidia may have laid the groundwork for a lot of this tech, but who will end up making the best use of it? We’ll no doubt find out come the end of the year when AMD launch their brand-new Navi cards.
