The first in the D-Series family, the IMG DXT will enable manufacturers to integrate ray tracing into their SoCs, addressing both premium and mainstream devices.
The market volume addressable by mobile ray tracing to date has been small but, according to Imagination, the IMG DXT will enable ray tracing to become a mainstream technology, justifying the interest and investment of mobile game developers and OEMs.
The GPU scales from an area-efficient half ray acceleration cluster (RAC) configuration up to a high-performance four-RAC design - covering a wide range of applications, from simple shadowing in hybrid implementations to premium ray-traced graphics for AAA content.
With support for Fragment Shading Rate (FSR) for Vulkan, IMG DXT frees up performance headroom for developers. FSR decreases the number of fragments processed and significantly increases graphics performance with minimal impact on visual quality. At the same time, FSR makes ray-traced effects more efficient as fewer rays are sent into the scene, meaning realistic lights and shadows are achieved within a smaller silicon area.
The flagship DXT-72-2304 configuration delivers 72 GTexels/s and 2.5 TFLOPs of FP32 arithmetic performance, with a 50% higher maximum single-core performance compared to the previous generation. DXT cores offer 20% better performance density per area than the IMG CXT GPUs, while significantly reducing power requirements.
Commenting David Harold, Chief Marketing Officer, Imagination said, “The growing mobile gaming market comes with a demand to balance low-power use against the desire for realistic and immersive graphics. As industry leaders in efficient ray tracing for mobile, we are accelerating ray tracing adoption and driving ecosystem growth. Last year, we launched and licensed the first mobile ray-tracing GPU. Our new scalable IMG DXT cores work at multiple levels of implementation, starting with basic graphics integrations, up to flagship SoCs with desktop-level ray-traced visuals. The mobile GPU launches today, and we have already licensed the IP in multiple segments. We are also speaking with lead partners in automotive, desktop and data centre.”
The IMG DXT GPU comes in several configurations and performance points. Mainstream device manufacturers looking to differentiate their offerings can choose the area-efficient half-sized ray acceleration cluster (RAC) configuration. OEMs looking for advanced performance can select from a single, dual, or quad-RAC configuration for the ultimate mobile visual experience.
DXT’s Photon architecture is currently the only ray tracing design that sits at Level 4 on the Ray Tracing Levels System (RTLS), which means it delivers its market-leading visuals in the most power-efficient manner available in the industry.
Imagination’s ray tracing solutions sit at Level 4 regardless of RAC configuration, ensuring DXT offers usable ray tracing at up to 40% lower area cost, compared to the same mobile configuration as CXT.
The fragment shader in a GPU draws the colours from a scene onto the framebuffer. FSR is a technique where the number of times the fragment shader runs is reduced with almost no decrease in image quality as a result. This cuts bandwidth usage and lowers power consumption.
Developers control how aggressively FSR is used, the most extreme mode executes the shader code only once for a 4x4 fragment zone, resulting in a near 94% reduction in workload with matching power and bandwidth benefits. The performance this frees up enables developers to do more with the hardware and offers players a higher-quality gaming experience.
Many cutting-edge games rely on heavy texture sampling to implement advanced filter effects. The IMG DXT GPU has an innovative special mode inside its texture processing unit (TPU) that creates a “fast path” for these post-processing effects. The result is a near doubling of bilinear filtering performance with minimal area growth and an overall reduction in power consumption. It accelerates tasks such as post-processing effects in games and computational photography filter processing. The higher throughput of the GPU also enables improved ray-traced image quality through faster and more power-efficient denoising algorithms.
The IMG DXT GPU also features a new shader processing unit (SPU) design. The SPU is a silicon block that contains both an arithmetic logic unit (ALU) for compute tasks and a texture processing unit (TPU) for shading pixels, geometry processing and rasterisation logic.
The DXT GPU delivers 50% more top-end compute and texture (ALU/TPU) performance per SPU, thanks to a new triple Universal Shader Cluster (USC) design (3x ALU/TPU units), where previous architectures focused only on a dual-USC design (2x ALU/TPU units). This improved building block enables the creation of Imagination’s highest-performance premium mobile GPU, the DXT-72-2304 which boasts 72 GTexels/s and 2.5 TFLOPs FP32 at a clock frequency of 1 GHz.
DXT includes support for a wider range of compression technologies to maximise bandwidth efficiency. This includes Khronos ASTC HDR, enabling textures to have a greater dynamic range between bright and dark areas while retaining detail.