At OCP in San Jose this week, Cisco and NVIDIA announced plans for an Ultra-Dense Small Form Factor Pluggable (USFP), a new high-density 400Gb/s-per-lane optical module designed to equip the hardware ecosystem for the next generation of AI factories using pluggable transceivers.
๐๐๐ฒ ๐๐๐ญ๐๐ข๐ฅ๐ฌ ๐จ๐ ๐ญ๐ก๐ ๐๐๐ ๐ ๐๐ง๐ง๐จ๐ฎ๐ง๐๐๐ฆ๐๐ง๐ญ:
๐๐๐ฐ ๐๐ฉ๐ญ๐ข๐๐๐ฅ ๐๐ญ๐๐ง๐๐๐ซ๐ - the USFP is designed to be the first module to support 400Gb/s-per-lane electrical signals.
๐๐๐ง๐๐ฐ๐ข๐๐ญ๐ก ๐๐ง๐ ๐๐๐ฉ๐๐๐ข๐ญ๐ฒ - it supports up to 12.8Tb/s of pluggable capacity for AI Ethernet fabrics, delivering 4x the bandwidth density and 1.3x the power efficiency of previous 200Gb/s-per-lane optics.
๐๐๐จ๐ฌ๐ฒ๐ฌ๐ญ๐๐ฆ ๐๐จ๐ฅ๐ฅ๐๐๐จ๐ซ๐๐ญ๐ข๐จ๐ง - Cisco and NVIDIA are working alongside hardware partners TE Connectivity and Amphenol to manufacture the required cages, connectors and modules.
๐๐ซ๐จ๐๐๐๐ซ ๐๐๐ ๐๐จ๐ฅ๐ฅ๐จ๐ฎ๐ญ - the launch aligns with Cisco's broader release of new Cisco Silicon One systems (including G300-powered systems and 1.6T G302 silicon) to scale open AI infrastructure.
๐๐๐ ๐ ๐ฏ๐ฌ ๐๐๐ - the difference between Cisco’s USFP and Arista’s XPO (backed by Coherent, Lumentum and the Open XPO MSA) comes down to competing visions on how AI data centers should solve the thermal wall and faceplate density limit.
Cisco’s USFP focuses on air-cooled and hybrid-cooled architectures. The company designed USFP around 400G-per-lane signalling to maximise electrical-to-optical efficiency and shrink module size, allowing operators to keep existing air-cooled rack designs without immediately overhauling facility plumbing. Meanwhile, Arista’s XPO is betting on direct liquid cooling. Each XPO module embeds a miniature liquid cold plate directly on the pluggable unit, allowing it to dissipate up to 400W per module.
๐๐ฎ๐ฉ๐ฉ๐ฅ๐ฒ ๐๐ก๐๐ข๐ง ๐๐ง๐ ๐๐ข๐ฅ๐ข๐๐จ๐ง ๐๐๐จ๐ฌ๐ฒ๐ฌ๐ญ๐๐ฆ๐ฌ - Cisco collaborates closely with NVIDIA and is aligning USFP with NVIDIA’s Spectrum-X networking roadmap and native Silicon One switch chips. Arista, meanwhile, relies on Broadcom merchant silicon and an open optical component supply chain (Coherent, Lumentum) through the Open XPO MSA.
๐๐ง๐๐ฅ๐ฒ๐ฌ๐ญ Take
• The two standards serve two distinct infrastructure deployment applications.
• USFP is targeted at hyperscalers and enterprises that want maximum faceplate density without requiring immediate liquid-to-pluggable plumbing in every server row. It acts as an evolutionary step for air-cooled high-density networks.
• XPO is targeted at massive single-site GPU clusters where rack power density exceeds 120kW per rack, making liquid cooling mandatory down to the transceiver module. Ultimately, as speeds reach 400G/800G per lane, both pluggable form factors (USFP and XPO) will face competition from CPO.
