Arm unveils Neoverse CSS N4 and expands AGI CPU ecosystem for agentic AI servers

On September 8, 2026 Arm announced Neoverse CSS N4, a configurable compute subsystem for partners that build their own data center chips, alongside an expanded AGI CPU ecosystem. Arm says CSS N4 supports up to 128 cores per die, LPDDR6 memory and PCIe Gen 7, and delivers up to 2x performance versus CSS N3 by its own comparison. Arm named AGI CPU partners including OpenAI, Meta, Cloudflare, Oracle, SAP, Lenovo, Supermicro and Verda.

• CSS N4: up to 128 cores per die, LPDDR6 and PCIe Gen 7 support
• Arm's claims versus CSS N3: up to 2x performance, 1.25x performance per watt, 1.75x memory bandwidth
• AGI CPU partners include OpenAI, Meta, Cloudflare, Oracle, SAP, Lenovo, Supermicro, Verda
• Volcano Engine (ByteDance) is bringing AGI CPU-powered agentic sandboxes to market