Arm C2-Ultra and Mali G2-Ultra NX debut with major CPU, GPU and ray tracing upgrades

Arm has unveiled CSS for Mobile 2, its latest reference compute platform for flagship SoCs. For starters, it seems to have ditched the Lumex branding entirely, just a year after it replaced the long-running Cortex as an identifier for Arm's CPU IP for smartphones. Previously, Arm has been known to skip new versions of its E-cores, and this time, the 'mid' core (Lumex C1 Premium) seems to have been left without a refresh. 

The new platform combines the new Arm C2-Ultra and C2-Pro CPU cores with Mali G2-Ultra NX graphics, an updated system interconnect and a new software stack. As with everything else announced in recent release cycles, AI remains the central focus. However, Arm’s approach extends well beyond conventional NPU-style acceleration. The C2 CPU cluster gains more SME2 compute for local models and agentic workloads, while the Mali G2-Ultra NX introduces dedicated neural accelerators directly inside its shader cores. Arm is also promising conventional CPU and GPU performance improvements for workloads that don't use AI.

An example flagship CSS for Mobile 2 implementation combines two C2-Ultra cores with six C2-Pro cores and two SME2 units, inadvertently giving us a look at what could very well be the MediaTek Dimensity 9600. Arm’s platform remains configurable, however, and chipmakers can use individual components independently, combine them with third-party IP, or modify the overall implementation to meet their own SoC requirements. For example, Samsung could replace the Mali GPU with its in-house Radeon design and Google could do the same with something from Imagination Technologies. 

Arm's new design has the CPU act as the orchestration layer for an agent, maintaining context and task state while deciding whether individual stages should run through local applications, on-device models, other accelerators or cloud services. Higher single-threaded performance reduces the latency of individual steps, while additional multi-thread performance lets retrieval, inference, and application activity run concurrently.

The new design ties these processors into Arm’s SI L2 system interconnect, which provides coherency, quality-of-service controls and higher-bandwidth, lower-latency communication between the platform’s different compute resources. Arm is also extending its optimisation work into the physical implementation stage, allowing partners to consider performance, area and power before integrating the IP into a finished SoC.

In Arm’s Neural Dawn demo, a combination of NFRU and NSSD delivered up to four times higher performance efficiency and cut external memory traffic by as much as 70% compared with native rendering. Arm argues that reducing conventional rendering work in this manner could make heavyweight Unreal Engine features such as MegaLights more practical on mobile hardware. NFRU can, for example, turn a 30 FPS render into a 60 FPS output. Arm is also positioning the technology as a route to sustained 120 FPS mobile gaming without requiring every displayed frame to be conventionally rendered, which is a fancy way of shoehorning frame-generation tech into mobile gaming. 

Thankfully, the Mali G2-Ultra NX is not relying exclusively on neural rendering for its generational gains. The GPU also introduces a redesigned execution engine, which Arm calls its largest Mali instruction-set architecture change in seven generations. Among other improvements, the architecture provides up to twice as many registers, giving complex shaders additional execution headroom.

Arm claims up to 24% higher benchmark performance from Mali G2-Ultra NX and up to 14% better non-AI gaming performance compared with the previous generation. Ray tracing hardware has been upgraded as well. G2-Ultra NX contains Arm’s third-generation Ray Tracing Unit and adds hardware support for Opacity Micromaps which can process complicated transparent geometry without imposing the same ray-tracing cost as conventional techniques.

Devices powered by the Mali G2-Ultra NX and C2-Ultra and C2-Pro will start showing up in the coming weeks. We can expect to see it power flagship designs from MediaTek at first, with Samsung’s Exynos 2700 expected to follow suit in early 2028. Qualcomm is also expected to unveil updated versions of its Nuvia and Adreno architectures alongside the Snapdragon 8 Elite Gen 6 and Snapdragon 8 Elite Extreme Gen 6 later this month. Even Apple is expected to join in on the fun with its A20 Pro SoC, slated to be unveiled alongside the iPhone 18 Pro series and iPhone Ultra.