876689-B21 HPE Synergy 300GB Interconnect 3M Cable

HPE 876689-B21 Synergy 300GB Interconnect Link 3M Active Optical Cable Overview

The HPE 876689-B21 Synergy 300Gb Interconnect Link 3M Active Optical Cable is a purpose-built optical link designed to extend and unify the composable fabric of HPE Synergy environments. This cable functions as a high-bandwidth, low-latency backbone connection between primary and satellite frames, enabling the Synergy architecture to distribute I/O and scale compute pools without excessive external switching complexity. Built to HPE's form, fit and interoperability standards, the 3 meter active optical cable (AOC) balances reach and manageability for modern data center topologies where speed, signal integrity and cable density matter.

Purpose

Within a Synergy deployment the interconnect link cable carries aggregated fabric traffic between master (primary) interconnect modules and satellite interconnect modules, consolidating traffic flows and enabling a true composable experience. Rather than treating each frame as an island, the interconnect link provides a tightly integrated method to extend the composable fabric across multiple frames—meaning pools of compute and storage can be composed and recomposed dynamically while preserving predictable performance and simplified management. The cable’s native compatibility with Synergy chassis and interconnects ensures plug-and-play installation and predictable operational behavior in multi-frame configurations.

Technical

The 876689-B21 is specified for 300 Gbit/s aggregated throughput, achieved through multi-lane optical transport and industry-standard signaling schemes used by HPE Synergy interconnect modules. This data rate supports modern east-west and north-south traffic patterns within converged rack systems, enabling high-performance workloads—such as virtualization, database clustering, AI/ML data shuttling, and high-speed SAN traffic—to maintain bandwidth headroom even under sustained load. The AOC design actively conditions and amplifies optical signals across the 3 meter distance to maintain low bit error rates while keeping electromagnetic interference concerns to a minimum compared with copper alternatives.

Active Optical Cable technology

Active Optical Cable technology integrates optical transceivers and fiber into a single cable assembly. Compared with passive copper direct-attach cables, AOCs offer several advantages relevant to data center operators: significantly lighter weight, smaller bend radius, immunity to electromagnetic interference, and the ability to sustain high data rates across distances that would be impractical for copper. The active components within the cable handle optical-electrical conversions and often include diagnostics that support link health visibility. For the Synergy environment this means easier cable routing inside frames and improved thermal and airflow characteristics because cables are slimmer and introduce less obstruction.

Form Factor

The 3 meter length is selected to match common data center layouts where primary and satellite frames are colocated within the same row or adjacent rows. The cable assembly uses HPE-specified connector types and mechanical keying, ensuring it mates correctly with Synergy interconnect ports and preventing accidental mismatches with non-compatible hardware. Many suppliers and HPE’s official SKUs also note availability in alternative lengths—such as 5m and 15m—and in low-smoke, zero-halogen (LSZH) variants for installations subject to stricter fire-safety or plenum requirements. Packaging and labeling follow HPE conventions for SKU 876689-B21 so inventory and procurement systems can easily map purchase orders to the correct item.

Compatibility

HPE markets this interconnect link specifically for use with Synergy frames and supported interconnect modules (including modules designed for 300Gb aggregated links). Compatibility lists and QuickSpecs identify the Synergy 12000 Frame and associated interconnect modules as compatible platforms. Using HPE-branded interconnect link cables and approved variants reduces the risk of unexpected incompatibility, link negotiation failures, or loss of warranty coverage. Customers building or expanding Synergy infrastructures should cross-reference the interconnect module firmware and the appropriate QuickSpecs to confirm the end-to-end supported configurations.

Choose AOC over DAC for Synergy interconnects

Designers must weigh the trade-offs between active optical cables and direct-attach copper. AOCs provide longer reach and lighter, more flexible cabling at higher aggregate speeds; DACs tend to be less expensive for very short distances but can be heavier and bulkier while being electrically susceptible to EMI. For multi-frame Synergy topologies where the interconnect link must cross small physical gaps between frames or route through management areas, AOC is often the practical choice because of its combination of reach, density and cleanliness of signal. Additionally, AOCs avoid potential electrical grounding or transient issues that sometimes appear with copper in complex rack environments.

Use-case scenarios

Architects deploy the 876689-B21 interconnect in several repeatable patterns: small-scale single-master plus satellite frame groupings within a rack row, larger multi-frame pools where a central master provides fabric services to several satellite frames, and hybrid environments where Synergy frames are colocated with traditional rack servers but require unified fabric connectivity. Use cases range from dense virtualization farms and VDI hosts to distributed storage clusters and network function virtualization (NFV). In each scenario, the cable’s 3 meter reach supports tidy intra-row cabling while delivering the performance necessary for converged application demands.

Comparisons

HPE offers a family of interconnect link cables for Synergy with different lengths and media types. The 876689-B21 covers the 3 meter AOC case, while other SKUs target 5m, 15m or passive copper lengths for very short connections. When comparing alternatives, consider physical routing constraints, budget, and the need for certifications like LSZH or plenum rating. In some situations, especially where frames are immediately adjacent and cost sensitivity is paramount, a direct-attach copper (DAC) option may suffice; where reach or EMI isolation matters, the AOC is the superior choice. Always cross-reference the HPE QuickSpecs to verify which SKU aligns with the chosen interconnect module and frame.

Documentation

Integrators should consult the HPE Synergy QuickSpecs, the cable data sheet and system installation guides for precise port mappings, electrical and optical tolerances, and supported firmware versions. These documents offer the authoritative compatibility matrix and recommended topologies needed to produce deployment plans, rack elevations and cut sheets. HPE’s product documentation also lists environmental ranges, mechanical specifications and the recommended handling instructions that installers should follow to maintain warranty and performance. Keeping these documents accessible during planning and installation avoids guesswork and enables reproducible deployments.