Imagination launches first mobile GPU core with level 4 ray tracing

Article By : Nitin Dahad

New flagship GPU from Imagination Technologies brings desktop-quality ray tracing to mobile for the first time and is industry’s first Level 4 RTLS ray tracing architecture.

Imagination Technologies has announced what it said is the first mobile GPU core which features ray tracing, with an architecture that meets level 4 of the ray tracing levels system. Its new IMG CXT is the latest flagship GPU intellectual property (IP) which debuts its PowerVR Photon ray tracing architecture.

The company said that by adding Photon hardware ray tracing, the IMG CXT represents another big jump in GPU IP, delivering incredible performance for games and other graphical use cases. Photon, the industry’s most advanced ray tracing architecture, brings desktop-quality visuals to mobile and embedded applications and has already been licensed for multiple markets.

In an interview on the latest embedded edge with Nitin podcast, Andrew Girdler, a product manager for GPUs at Imagination Technologies, explained, “This is a new GPU, a brand new IP that will be integrated into phones and tablet devices in the future. It basically adds ray tracing capability to our GPU – something that’s previously been reserved for high end desktop gaming experiences now with a new architecture we call the photon architecture. It’s the most advanced ray tracing architecture out there today, giving you the ability to enable advanced ray trace gaming effects, in a low power budget in a mobile phone device. We’re able to get some really nice shadows, reflections, these kinds of things you want in your game that look really great and we’re able to get those in a mobile phone power budget with ray tracing which is really exciting and the first time that someone can be enabling this level of solution in this space.”

Ray tracing is a technology that delivers a step-change in graphics realism. By imitating how light behaves in the real world it makes it possible to create 3D scenes that are near indistinguishable from real life. Due to its computational complexity, ray tracing has only recently come to desktop PCs and gaming consoles, but with the IMG CXT’s “revolutionary” Photon architecture, mobile developers and gamers are also now able to take advantage of this rendering technology with full hardware acceleration. Photon brings ray tracing to applications such as mobile, gaming, augmented reality (AR), desktop, data center, cloud, and next-generation automotive.

Girdler said the Photon architecture represents a decade of development in making ray tracing viable in low-power-enabled devices and delivers a major leap in the visual possibilities for smartphones, tablets, laptops, and automotive solutions. Ray tracing can be performed with varying levels of performance and efficiency and to highlight this Imagination established the Ray Tracing Levels System (RTLS), identifying six levels of ray tracing, from Level 0 to Level 5. The Photon architecture inside IMG CXT sits at Level 4 of the RTLS, making it the most advanced currently available, enhancing ray tracing performance and efficiency to deliver a desktop-quality experience for mobile gamers and developers.

The IMG CXT-48-1536 RT3 core features three instances of Imagination’s ray acceleration cluster (RAC), offering up to a total of 1.3GRay/s. This delivers photorealistic ray traced shadows, reflections, global illumination, and ambient occlusion, with high frame rates, in a mobile power budget.

Imagination Technologies CXT RT3 Block Diagram
The IMG CXT-48-1536 RT3 core features three instances of Imagination’s ray acceleration cluster (RAC), offering up to a total of 1.3GRay/s. This delivers photorealistic ray traced shadows, reflections, global illumination, and ambient occlusion, with high frame rates, in a mobile power budget. (Source: Imagination Technologies)

The IMG CXT also claims to be a significant step forward for rasterized graphics performance, with 50% more compute, texturing, and geometry performance than Imagination’s previous-generation GPU IP. Its low-power superscalar architecture delivers high-performance at low clock frequencies for exceptional FPS/W efficiency, while Imagination image compression (IMGIC) greatly reduces bandwidth requirements.

Multi-core scaleability for PC and data center

The Photon architecture can be scaled to cloud, data center and PC markets as a result of Imagination’s multi-core technology. This can generate up to 9TFLOPS of FP32 rasterized performance and over 7.8GRay/s of ray tracing performance, all while offering up to 2.5x greater power efficiency than today’s Level 2 or 3 RTLS ray tracing solutions.

IMG CXT is suited for ultra-premium automotive human-machine interface (HMI) platforms. It enables the photorealistic representation of vehicles for surround view and dense urban areas for sat-navs, as well as mixed-reality heads-up displays (HUDs), digital speedometers and other information displays. It can also deliver premium in-car gaming and entertainment experiences while occupants wait for the vehicle to charge.

Jon Peddie, president and founder, Jon Peddie Research, said, “Imagination Technologies pioneered hardware-accelerated ray tracing 10 years ago and has scaled it for the mobile market with its new PowerVR Photon architecture. As Imagination’s first Level 4 RTLS IP, CXT offers developers a hardware block dedicated to accelerating ray tracing that promises more power and area efficiency than other solutions. Consumers have come to appreciate the realism ray tracing provides and now will demand it in all their devices in the near future.”

Simon Beresford-Wylie, CEO, Imagination, commented, “As a key enabler of the smartphone revolution, Imagination has a distinguished track record of bringing cutting-edge 3D graphics to mobile devices. The innovations we have developed in high-efficiency ray tracing are another significant step in this journey and are creating an entirely new capability for the mobile graphics industry. We are excited to be working with our partners to realize the vision of putting photorealistic graphics content into the palm of your hand.”

Photon architecture in depth

The PowerVR Photon architecture features the RAC, a new low-power, dedicated hardware GPU block which accelerates and offloads more of the ray tracing computations from the shader cores compared to less-efficient Level 2 RTLS architectures.

Imagination Technologies Photon RAC Block Diagram
Imagination Technologies said the features of the ray acceleration cluster (RAC) combine to deliver greater and more consistent ray tracing performance for developers than current solutions on the market, enabling them to deliver more advanced effects when rendering complex surfaces such as cars, characters, and terrain, to create more detailed environments than ever before. (Source: Imagination Technologies)

The RAC consists of the ray store, ray task scheduler and coherency gatherer and is closely coupled to two 128-wide unified shading clusters (USCs) featuring high-speed dedicated data paths for the most efficient and lowest-power ray traced deployment. The ray store keeps ray data structures on-chip during processing, providing high-bandwidth read and write access to all units in the RAC, avoiding slowdowns or power increases from storing or reading ray data to DRAM. The ray task scheduler offloads the shader clusters, deploying and tracking ray workloads with dedicated hardware, keeping ray throughput high and power consumption low. The unique coherency gatherer unit analyzes all rays in flight and bundles rays from across the scene into coherent groups enabling them to be processed with much greater efficiency.

These features combine to deliver greater and more consistent ray tracing performance for developers than current solutions on the market, enabling them to deliver more advanced effects when rendering complex surfaces such as cars, characters, and terrain, to create more detailed environments than ever before.

An excited games industry

Girdler said various game studios including Tencent, Netease, and others are excited about the new GPU core’s capability. “We’re seeing great engagement because obviously ray tracing is very exciting technology. And bringing those game developers in with us, we’re working on next generation devices. They’re very excited already to be to be looking at that and thinking about what they plan for the future. Our ecosystem team has been doing some great work reaching out and working with those partners to help give them a bit of a view into the future of what sort of hardware is going to be out there and everyone, is just really excited to start to enable these effects in such a small low power device.”

Imagination Technologies PowerVR-GPU-CXT

Travis Boatman, CEO, Carbonated Inc, said, “At Carbonated, veterans from Zynga, Electronic Arts and Blizzard, we’re excited about Imagination Technologies leading the future of mobile GPU and ray-tracing technologies. It is important for us to optimize Mad World, our squad-based mobile PVP game, on O3DE for Imagination’s PowerVR architecture to enable the best playing experience for all of our players.”

Xu Dan, head of technical center, Perfect World Games, commented, “Perfect World Games and Imagination have a shared vision for a new generation of GPUs, based on the PowerVR architecture, to achieve high performance and low power consumption.” He added, “We hope to explore the application of this technology in games and other scenarios together.”

Wei Nan, engine technical deputy director, Tencent Games, said, “Ray tracing is regarded as the next generation of the graphics technology revolution and is the direction that Tencent Games continues to explore. We are very pleased to see Imagination, the industry leader in ray tracing technology, release hardware ray tracing IP. We will work closely to explore the application of this technology in games. Imagination has many years of experience in graphics rendering and processing with high performance and low power consumption. Together, we will strengthen our technical cooperation to achieve a leap in the quality of the gaming experience.”

Awen Cao, technical director, Tencent WeTest/PerfDog, added, “We believe that the new generation of PowerVR-architecture GPUs, with their high performance and lower power consumption, can help developers achieve better gaming performance. WeTest/Perfdog will work with Imagination to continuously optimize and improve the acquisition of key GPU parameters to support developers to create better gaming experiences and stronger platform compatibility. In the future, both will explore additional cooperation in ray tracing, cloud gaming and other fields.”

Meanwhile, Wenyao Li, senior technology expert, NetEase Games, said, “NetEase Games attaches great importance to experience, technology, and quality. NetEase and Imagination have been jointly optimising Messiah and Neox, NetEase’s self-developed engine.  The CXT GPU provides support for achieving a high-quality gaming experience, and in the future, we will take advantage of the high performance and lower power consumption of PowerVR-architecture GPUs in gaming development to create amazing experiences. We’re also looking forward to Imagination’s ray tracing technology, which will open a new era of graphic rendering and vision and hope we can explore its application in games together.”

To hear the full interview with Andrew Girdler, listen to the embedded edge with Nitin podcast here.

This article was originally published on Embedded.

Nitin Dahad is a correspondent for EE Times, EE Times Europe and also Editor-in-Chief of With 35 years in the electronics industry, he’s had many different roles: from engineer to journalist, and from entrepreneur to startup mentor and government advisor. He was part of the startup team that launched 32-bit microprocessor company ARC International in the US in the late 1990s and took it public, and co-founder of The Chilli, which influenced much of the tech startup scene in the early 2000s. He’s also worked with many of the big names—including National Semiconductor, GEC Plessey Semiconductors, Dialog Semiconductor and Marconi Instruments.


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