Unearthing the Holy Grail: real-time ray tracing on PowerVR GR6500 at CES 2016

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Jan 7, 2016  |  2 min read

Graphics on mobile devices have seen an incredible evolution in the last decade.

Imagination revolutionized the handheld industry in 2001 by launching a family of PowerVR GPUs designed for the very first wave of smartphones. Since then, we’ve set the standard for ultimate performance and energy efficiency with every release of the PowerVR graphics architecture.

About two years ago, a new revolution was quietly beginning. At GDC 2014, my colleagues introduced PowerVR Wizard, a new and scalable GPU architecture capable of running high-performance, real-time ray tracing applications in a tiny power budget.

Recently, I reported on an important milestone for the PowerVR Ray Tracing project: our GR6500 GPU is now working at full speed on a 28nm chip integrated on a PCIe evaluation board.

The most exciting thing about the PowerVR GR6500 GPU is that it is a complete graphics engine with additional ray tracing capabilities. Developers give up absolutely nothing to get access to ground-breaking ray tracing capabilities.

To really make this point, we are showing a special preview at CES 2016 of our entire test suite of existing PowerVR software, without any modifications, on the GR6500-powered development system.


The ray tracing hardware in the GR6500 opens the door to many advanced graphics algorithms that have previously been out of reach on all but highest end desktop GPUs consuming hundreds of watts.


In a post last year, we described how shadows, reflections and refractions could be integrated into a traditional raster game engine pipeline. And in this follow-on article, we looked at how using the ray tracer for shadows produces better results with fewer artifacts, and equally importantly it is actually more efficient than computing shadows with the state of the art cascaded shadow maps method.

The GR6500 GPU allows every part of the hybrid Unity game engine to run concurrently on the same GPU.  Both the raster and ray tracing passes are executed simultaneously and data flows efficiently through the rendering pipeline keeping costly context switches and power hungry memory traffic to an absolute minimum.

09_Ray tracing in games_PowerVR Ray Tracing - hybrid rendering-1-label

In the image above we’re showing how ray tracing can be used for selective effects in a game, but famously ray tracing is the cornerstone of an altogether different class of rendering: physically-based path tracing.

Path tracing, as the name suggests, employs the laws of physics to calculate exactly how much light reaches a pixel of the image with a virtual camera. This makes it ideal for rendering images with uncompromising photorealism and also shortens the content creation process drastically by allowing the artist to work in familiar materials, e.g. wood, stone and glass, and by placing lights instead of using the huge bag of tricks needed to do high performance rendering.

Previously, path tracing was confined by its slow speed to offline workflows like architectural visualizations and cinematic special effects.  Empowered by the PowerVR GR6500, path tracing can now run at interactive speeds and with unprecedented power efficiency.  Path tracing is poised become an important part in emerging uses of graphics including VR and AR as they mature.

PowerVR Wizard Ray Tracing - Production quality renderingAn image rendered using production quality rendering methods on the development system

The PowerVR GR6500 is a mobile GPU. Its die size, GFLOPS performance, bandwidth requirements and power consumption mean that it is comparable to the GPUs already available in smart phones today. But compared with a console GPU or looking towards the smart phones and handheld devices of the future, we see a roadmap that scales in capabilities and performance well beyond the GR6500’s specifications. The PowerVR Ray Tracing technology is fundamentally scalable and the efficiency actually increases as we move to more and more powerful cores.

To demonstrate this scalability, we are showing several of the GR6500 boards working inside the same system.

PowerVR Wizard Ray Tracing - PCIe eval boardThe PowerVR Wizard PCIe evaluation board powering the demos above

This configuration gives us a proof point for high throughput ray tracing, in excess of a billion rays per second. Ultimately, we can provide our licensees with a full performance development environment, already in silicon, for any ray tracing GPU on the roadmap. With room to run, this is just a small taste of what is possible with the PowerVR Wizard architecture.

PowerVR Wizard Ray Tracing at CES 2015Scaling across multiple PowerVR GR6500 GPUs

We’re really excited about the prospects of our PowerVR Wizard ray tracing architecture and how developers will use it to create the next generation of graphics-intensive applications. If you want to know more about the PowerVR GR6500 GPU and the demos previewed above, join us at GDC 2016 for a series of presentations or visit our booth on the show floor to experience our ray tracing technology live.

Make sure you follow us on Twitter (@ImaginationTech) to get the latest news and announcements for the PowerVR ecosystem.

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Here at Imagination, our vision is to be the undisputed leader in semiconductor IP solutions that transform billions of lives.

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