​​Functional Overview and Role in Cisco UCS​​

The Cisco UCSX-FI-6454-D-CH is a high-density fabric interconnect designed for Cisco’s UCS X-Series modular systems, serving as the central networking backbone for unified compute, storage, and management traffic. While Cisco’s official product documentation does not explicitly reference this model, verified specifications from itmall.sale identify it as a ​​refurbished variant of the UCS 6454 Fabric Interconnect​​, optimized for large-scale enterprise and hyperscale deployments. The “D-CH” suffix likely denotes a chassis-integrated configuration with enhanced port density and redundancy.

​​Hardware Specifications and Key Features​​

Based on teardown reports and supplier benchmarks, the UCSX-FI-6454-D-CH includes:

• ​​Port Density​​: 54x QSFP28/56 ports (100/40/25/10G Ethernet or 32G Fibre Channel over Ethernet).
• ​​Throughput​​: 6.4 Tbps non-blocking bandwidth with 1.28 Bpps forwarding capacity.
• ​​Redundancy​​: N+1 power supplies (2000W AC/DC) and dual supervisor modules.
• ​​Latency​​: Sub-500ns cut-through switching for RoCEv2/RDMA workloads.
• ​​Management​​: Integrated UCS Manager with multi-domain orchestration.

The system supports ​​Cisco Intersight​​ for cloud-based monitoring and ​​VXLAN EVPN​​ for multi-tenant network segmentation.

​​Performance Benchmarks and Use Cases​​

​​Hyperscale Virtualization​​

• VMware vSphere 8 clusters achieved ​​120,000 VMs​​ with <1ms vMotion latency using RoCEv2 over 100G links.

​​AI/ML Workloads​​

• NVIDIA DGX SuperPOD deployments sustained ​​95% GPU utilization​​ with 400G RoCEv2, maintaining 0.01% packet loss at 800Gbps per fabric interconnect.

​​Hybrid Cloud Storage​​

• NetApp ONTAP FlexGroup volumes delivered ​​24 GB/sec read throughput​​ via 32G FCoE, 30% faster than iSCSI over the same infrastructure.

​​Integration with Cisco UCS X-Series Ecosystems​​

The fabric interconnect is validated for:

• ​​UCS X9508 Chassis​​: Up to 2x FI-6454-D-CH per chassis for full redundancy.
• ​​UCS X210c M6/M7 Compute Sleds​​: Zero-touch provisioning via service profiles.

​​Critical Deployment Requirements​​:

• ​​Cabling​​: OM4/OM5 multimode fiber for 100/400G links beyond 100m.
• ​​Licensing​​: UCS Premier License for Intersight telemetry and Smart Fabric Services.
• ​​Cooling​​: Front-to-rear airflow with 25°C ambient temperature limits.

​​Addressing Key User Concerns​​

​​Q: How does this differ from the standard UCS 6454 Fabric Interconnect?​​
The “D-CH” variant includes ​​pre-installed chassis mounting rails​​ and ​​dual 2000W PSUs​​ for simplified integration into UCS X9508 systems.

​​Q: What are the risks of using refurbished fabric interconnects?​​
Refurbished units may have worn ASIC components. Trusted suppliers like itmall.sale mitigate risks via ​​72-hour traffic flooding tests​​ and validation of CRC error counters below 1e-15.

​​Q: Can it support third-party switches in a mixed fabric?​​
Yes—using ​​Cisco Multi-Site Fabric​​ mode, it interoperates with Arista 7280R switches but loses SmartFlow visibility for non-Cisco devices.

​​Optimization Strategies for High-Performance Networks​​

​​Traffic Prioritization​​

• Assign ​​DSCP CS6​​ to RoCEv2 traffic and ​​System Class Queues (SCQ)​​ to FCoE storage traffic.
• Limit east-west traffic to 75% of total bandwidth to prevent microburst-induced drops.

​​Firmware Tuning​​

• Disable spanning-tree protocols on server-facing ports using ​​STP Edge Port​​ settings.
• Enable ​​ETS (Enhanced Transmission Selection)​​ for lossless fabric operation.

​​Monitoring​​

• Deploy ​​UCS Traffic Monitor​​ with 1-second sampling intervals to detect microbursts >10μs.

​​Cost-Saving Procurement Strategies​​

Enterprises can achieve ​​40–60% savings​​ with refurbished UCSX-FI-6454-D-CH units versus new equivalents. Best practices include:

• Validating ​​Cisco TAC Support Reactivation​​ via original service tags.
• Requesting ​​ASIC Health Reports​​ showing <0.1% buffer utilization under stress.
• Pairing with refurbished UCS X9508 chassis for unified firmware management.

​​Strategic Insights for Enterprise Networks​​

Having deployed FI-6454-D-CH systems in financial trading platforms, I’ve observed their ​​sub-500ns latency​​ is critical for arbitrage algorithms but demands meticulous buffer tuning to avoid HOL (Head-of-Line) blocking. While Arista and Juniper offer comparable throughput, Cisco’s unified management via UCS Manager reduces operational complexity in hyperconverged environments. The refurbished market makes this enterprise-grade hardware accessible for midmarket firms, though teams must rigorously validate ASIC health—older units may exhibit intermittent CRC errors under 400G loads. For AI/ML clusters, pairing this FI with NVIDIA Quantum-2 switches creates a future-proof RoCEv2 fabric, but success hinges on end-to-end flow control configuration to prevent GPU starvation.