Real-Time Ray Tracing on Intel® Arc™ Graphics

The tech which makes 3D movies look stunning has arrived in gaming and Intel Arc GPUs are fit to enhance games visuals with rays. Ready to step into the light with Intel?

Intel has been unveiling Intel Arc graphics’ suite of tech features lately, including X^e Super Sampling and HDR & VRR support. Another feature we’re excited to talk about is real-time ray tracing for games. Ray tracing is a method for simulating how light behaves with light paths traced from each pixel on screen, bounced off objects, and connected to their light origin. This method, technically called path tracing, allows for super realistic shading, reflections, refractions, and shadows in a way traditional rasterization graphics pipelines simply don’t.

Since it’s important to understand the difference, this distinction is the first topic of this video. Rasterization is the traditional method for rendering 3D scenes in games. Game objects in 3D space are projected onto a 2D plane (your monitor) with the color, texture, reflections, and of course shading all handled by subprograms called shaders. This method isn’t going away anytime soon – every game still uses raster techniques even if it supports ray tracing.

Rasterization is fast, effective, and established, so it allows developers to implement hybrid rendering and apply ray tracing to a few select areas instead of ray tracing the entire scene, which would be too intense for current computers to run smoothly. Gaming APIs such as DXR and Vulkan RT have been designed with hybrid rendering in mind and help developers improve rasterized renders with ray tracing effects.

Why is rasterization “stupid fast?” Intel and other GPU vendors have developed, and optimized over 2 decades, a set of specialized fixed-function hardware to assist compute engines such as X^e -cores. With Arc GPUs, ray tracing takes advantage of its own specialized hardware too with the new Ray Tracing Units (RTU). Each RTU includes two Ray Traversal Pipelines to quickly trace rays through the geometry structure and can handle 12 box intersections and a triangle intersection per cycle.

This set of ray tracing hardware gives Arc GPUs not only great peak rates but also great throughput in real world uses of ray tracing. But the X^e architects didn’t stop there: the last piece of this puzzle is our Thread Sorting Unit which helps implement what we call Asynchronous Ray Tracing. This deals with ray divergence and combines rays with similar hit shaders to ensure maximum utilization of the X^e-cores in simple and more complex scenes. All a bit techy? Perhaps colored boxes will help:

Let’s come up for air from this deep dive! Ghostwire: Tokyo is an excellent example of ray tracing with a load of lights and a surfeit of shiny surfaces. In our side-by-side comparison starting at 17:06 you can see TAP’s game on the left with RT on, and my game with RT off – but mine does include reflections in the form of “screen space reflections.” Tom’s reflections are persistent, crisp, and don’t disappear. I didn’t die in this game, but the blurry screen space reflections expired as soon as the object they were reflecting was off-screen, a limitation of rasterization techniques.

Looking for performance numbers? Our video isn’t complete without them! We’ve shown plenty of Intel Arc A750 graphics performance, now we’re looking at the top-end Arc A770 GPU running games at 1080p­­­­. Again, comparing to the Nvidia RTX 3060, the chart below shows performance in over a dozen ray traced games – see our configuration info at the bottom of this article. While putting this info together, our engineers delivered a fresh driver which improved performance in Ghostwire Tokyo by up to 25%!

Let’s combine tech! With ray tracing on and X^eSS enabled, but moving up to 1440p resolution:

Hats off to the stellar Intel engineers who have made this possible for the benefit of all us gamers who crave performance and visual quality. We hope you’ve enjoyed this dive into our ray tracing technology and its performance; we’ll be back soon with a teardown of an Intel Arc Limited Edition card and more technical info!

Notices and Disclaimers

Performance varies by use, configuration and other factors. Learn more atwww.Intel.com/PerformanceIndex (graphics and accelerators).

​Performance results are based on testing as of dates shown in configurations and may not reflect all publicly available ​updates. No product or component can be absolutely secure.​​

Intel does not control or audit third-party data.  You should consult other sources to evaluate accuracy.

Intel technologies may require enabled hardware, software or service activation.

All product plans and roadmaps are subject to change without notice.

Statements that refer to future plans or expectations are forward-looking statements. These statements are based on current expectations and involve many risks and uncertainties that could cause actual results to differ materially from those expressed or implied in such statements. For more information on the factors that could cause actual results to differ materially, see our most recent earnings release and SEC filings at www.intc.com.

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