Arm unveils CSS for Mobile 2 with C2 CPU cluster, up to 1.7x faster on AI models
Arm has introduced Arm CSS for Mobile 2, a compute platform for smartphone chips that combines the C2 CPU cluster, the Mali G2-Ultra NX GPU and the SI L2 system interconnect. The C2 cluster pairs C2-Ultra and C2-Pro CPUs with two SME2 units, the Scalable Matrix Extension 2 that speeds up matrix math for AI on the CPU. Arm says this doubles the SME2 capability of the previous-generation configuration and reports up to 1.7x performance across the latest AI models.
The cluster delivers up to 15% higher single-thread performance, 15% faster web browsing, 12% faster app launch and 12% higher multi-thread performance, Arm reports. For AI, it cites a peak uplift of up to 70% in selected tasks. Its slide compares speech, personal memory retrieval and prefill, the phase where a model reads the prompt, against the C1-Ultra with SME2. In a representative agentic workflow covering speech processing, memory retrieval, reasoning, app execution and web browsing, the C2-Ultra with two SME2 units finishes 24% faster than the previous generation, according to Arm.
The example flagship configuration in Arm’s slides has two C2-Ultra and six C2-Pro cores. The Mali G2-Ultra NX GPU integrates neural accelerators into its shader cores and adds a new execution engine and a third-generation ray tracing unit for neural graphics. Arm says the SI L2 interconnect provides lower-latency access, higher bandwidth, coherency and quality-of-service controls for CPU, GPU and other resources working at the same time. Partners can use each component on its own or combine them with custom and third-party IP.
On the software side, Arm lists KleidiAI, its optimized libraries for Arm CPUs including SME2 paths, plus integrations with common AI frameworks. The Arm AI Portal offers validated models with performance and accuracy data, code examples and deployment resources, and the Arm MCP Server connects them to agentic development tools. vivo says it is bringing Arm Neural Technology to its latest flagship smartphones built on the platform, aimed at mobile gaming. Arm’s post names no launch dates for devices with CSS for Mobile 2.