Arm today announced its new flagship Immortalis GPU, the first to include hardware-based ray tracing on mobile. While PCs and the latest Xbox Series X and PS5 consoles are all gradually evolving towards impressive ray-traced visuals, the Immortalis-G715 is designed to be the first Arm GPU to deliver the same on Android phones and tablets.
Built on Mali, a GPU used by MediaTek and Samsung, Immortalis is designed with 10-16 cores in mind and promises a 15 percent boost over the previous generation of premium Mali GPUs. Arm sees Immortalis as the beginning of a move to ray tracing on mobile after its success with the 8 billion Mali GPUs shipped to date.
“The challenge is that Ray Tracing techniques can use a lot of power, energy and surface area in the mobile system-on-a-chip (SoC),” explains Andy Craigen, director of product management at Arm. “However, Ray Tracing on Immortalis-G715 uses only 4 percent of the shader core area, while delivering over 300 percent performance gains through hardware acceleration.”
Arm is already delivering software-based ray tracing in last year’s Mali-G710, but the promise of hardware support means we’ll see flagship smartphones with this chip in early 2023.
“We’ve decided to introduce hardware-based Ray Tracing support now on the Immortalis-G715 because our partners are ready, the hardware is ready, and the developer ecosystem is ready (about to be ready),” said Craigen. Arm offers just a few samples of ray tracing on its mobile GPUs today, and there’s no clear commitment from game developers yet.
Arm has also updated its main Mali line with the Mali-G715. This GPU includes variable speed shadow (VRS) to improve game performance and power saving on mobile. VRS essentially renders the parts of a scene in a game that require more detail, so details in the background don’t need as much rendering power. “When enabling Variable Rate Shading on game content, we’ve seen improvements of up to 40 percent at frames per second,” Craigen claims. Other improvements mean these latest Arm GPUs will see a 15 percent power efficiency improvement over the previous Mali-G710 GPU introduced last year.
Arm’s move to support hardware-based ray tracing on its GPUs is an important step for Android mobile gaming. Ray tracing is currently limited to high-performance GPUs typically found in gaming PCs or the latest Xbox Series X and PS5 consoles. Nvidia previously demonstrated ray tracing paired with Arm last year, but it was an RTX 3060 GPU paired with a MediaTek Kompanio 1200 Arm processor. That effort is focused on PCs and likely Chromebook-style laptops, but Arm’s new Immortalis is completely focused on Android.
Epic Games supports Immortalis with its Unreal Engine, in addition to MediaTek and Unity. This is the kind of industry support you’d expect for a new mobile GPU like this, but the real test will be how much mobile game developers are going to implement ray tracing. It’s still incredibly rare to see ray tracing on console games, so it’s unlikely we’ll see a flow of mobile games to ray tracing anytime soon.