Arm G715 GPU Catches Some Rays

Ray tracing in smartphones takes a big step with Arm’s new Immortalis-G715 GPU, while the Mali-G715 version brings new features and better performance to mainstream devices.

Joseph Byrne

The G715 is Arm’s first GPU generation to offer ray-tracing hardware, accelerating this function by 4x. Almost nonexistent in smartphones but common in desktop PCs, ray-tracing hardware enhances the realism of 3D scenes. Reflections on surfaces such as glass and ice appear more natural, and improved lighting enlivens characters. We expect the first G715-powered handsets to reach gamers in early 2023.

The company is also inaugurating a new brand, Immortalis. Reserved for the most powerful GPU configurations, that name applies to G715 models with 10 or more shader cores and the ray-tracing unit (RTU) enabled. Lesser configurations of the new design will go by the familiar Mali name: Mali-G715 for those with seven, eight, or nine cores, and Mali-G615 for those with fewer. Lower-cost chips will still use the Mali-G510 and Mali-G310 profiles from the previous GPU generation.

The fourth iteration of the company’s proven Valhall architecture, the G715 also doubles peak floating-point throughput, adds variable-rate shading, and hones the design of the G710 generation to squeeze out more performance while consuming less energy. Overall graphics performance increases on average 15% compared with the G710 in the same process, with power remaining the same.

Rival intellectual-property (IP) supplier Imagination Technologies has offered hardware ray tracing since acquiring Caustic Graphics in 2010, but its licensees have yet to bring any such chips to production. The only shipping smartphone processor with this feature is Samsung’s Exynos 2200, which integrates AMD GPU technology. Ray-tracing acceleration has appeared in GPU cards from AMD and its PC rivals for the past few years, and many popular PC games employ it. Thus, mobile versions of these games should adopt this feature quickly once it is available in popular smartphones.