Arm Licenses Neoverse N2 Subsystem

Arm’s new licensable Neoverse CSS N2 provides an entire compute subsystem implemented and verified on TSMC’s 5 nm process. It may save customers months of work.

Bryon Moyer

Arm, known for licensing CPUs and other computing blocks, is licensing a full subsystem that integrates its Neoverse N2 CPU. Chip designers looking to differentiate elsewhere will have a head start because they no longer need to design that subsystem.

Available now, the Neoverse CSS N2 connects up to 64 N2 CPUs through a central mesh network, adding multiple accelerator ports, system and memory controllers, and an interrupt controller. Ports are available for additional memory, peripherals, and Compute Express Link (CXL) connections. The CPU clock runs up to 3.6 GHz; Arm estimates SpecRate2017Int to be 250 at 3.0 GHz. It estimates power for a 64-core implementation to be between 50 W and 100 W.

Having offered CPUs for years, Arm provides multiple reference platforms. But those designs are suggestions; customers must still implement them using the manufacturing process of their choice, verifying performance and compliance with any Arm architecture or other requirements. The CSS N2 marks the first time Arm has licensed a full implementation. Validated on TSMC’s 5 nm process, it’s portable to any node.

Arm has a dominant position in embedded systems and cellphones based on their Cortex CPUs. Neoverse takes those cores and, with some changes, markets them for servers and high-end embedded systems. The company is playing catch-up in those x86 strongholds but already has Neoverse wins at Amazon, Alibaba, Marvell, and Nvidia.

The company also detailed the changes made to the Neoverse V2 compared with the V1. The V2 is essentially the same as the Cortex-X3 and is more powerful than the N2, which is based on the Cortex-A715. The new disclosures reveal each changes’ performance impact; taken together, they raise the V2’s SpecInt throughput 13% over that of the V1.