Extra-Dense Pluggable Optics Module Achieves 12.8 Tbits/sec
Arista Networks recently formed the XPO Multi-Source Agreement (MSA), which is “focused on defining and standardizing a next-generation, high-density, liquid-cooled pluggable optics module engineered to meet the extreme bandwidth and thermal demands of AI-driven data center architectures,” said XPO MSA founding member Aperion Technologies when announcing its participation in the effort.
Arista added, “XPO was designed specifically to support AI networking including scale-up, scale-out, scale-across, and metro reach fabrics,” emphasizing the new module offers the following breakthroughs.
- 12.8 Tbits/sec per pluggable module
- 204.8 Tbits/sec per Open Compute Project (OCP) rack unit (OU)
- Integrated cold plate capable of cooling up to 400W power per module
- Support for all industry optics standards including DR, FR, LR, SR, ZR/ZR+ along with next-generation coherent-lite, slow-and-wide, copper, and RF/microwave.
- Flexibility to support linear, half-retimed, or fully retimed interface architectures
Andreas Bechtolsheim, Arista Networks’ chief architect, commented, “The unprecedented growth in AI fabric bandwidth and the transition to liquid cooling requires a new generation of pluggable optics modules. XPO resolves this challenge by providing fundamental improvements in density, cooling capability, and reliability for pluggable optics modules.”
Aperion’s chief technology officer Al Bonzoni added, “XPO represents a fundamental rethinking of pluggable optics for the liquid-cooled data center era. The explosive bandwidth growth of AI data centers is fundamentally reshaping infrastructure requirements. XPO combines breakthrough bandwidth density and advanced liquid cooling with the serviceability advantages of pluggable architectures to push hyperscale data center infrastructure into the next era of performance. As a dedicated optical module innovator, Aperion is proud to help define the XPO standard. Delivering step-function improvements in density and thermal performance is essential to sustaining AI scale, and we are committed to advancing this next generation of pluggable optics.”
In a white paper introducing XPO and describing its value, Arista notes, “While the industry-standard OSFP (Octal Small Form-Factor Pluggable) module has successfully enables, 400G, 800G, and 1.6T optical pluggable modules, it is limited to 32 modules per RU, typically requiring 2 RUs to achieve 102.4 Tbits/sec and 4 RUs to reach 204.8 Tbits/sec of switching capacity. Although co-packaged optics (CPO) and on-board optics (OBO) have been proposed to increase bandwidth density, these approaches introduce significant challenges in field serviceability, scalability, and manufacturability, making them difficult to deploy widely in hyperscale environments.
“XPO represents a new class of optical pluggable module designed specifically for next-generation AI data center fabrics. Each XPO module delivers 12.8 Tbits/sec of bandwidth using 64 electrical lanes and incorporates an integrated liquid-cooled cold plate capable of supporting 400W+ module consumption. The XPO is approximately 2.7x wider than the OSFP form factor and delivers x8 higher bandwidth per module, enabling up to 204.8 Tbits/sec of switching capacity within the vertical space of a single Open Rack Unit (1OU)—a 4x increase in front-panel density compared to OSFP."