Cisco RD-DPX80-X40-K9: High-Density 400G Data Plane Module for Next-Gen Data Center Fabrics

Product Overview and Core Functionality

The ​​Cisco RD-DPX80-X40-K9​​ is a ​​400G-capable data plane module​​ designed for the ​​Cisco Nexus 9000 Series switches​​, enabling hyperscale data centers and cloud providers to transition from legacy 100G/40G infrastructures to high-speed 400G architectures. This module supports ​​OSFP (Octal Small Form Factor Pluggable)​​ interfaces, providing ​​8x400G ports​​ or ​​32x100G breakout connectivity​​ with hardware-accelerated forwarding for AI/ML workloads, distributed storage, and east-west traffic optimization.

Technical Specifications and Architectural Design

​​Performance and Scalability​​

• ​​Throughput​​: 3.2 Tbps full-duplex, non-blocking.
• ​​Buffer Capacity​​: 12 GB shared packet buffer (HBM2 memory) for elephant flow management.
• ​​Latency​​: <500 ns (cut-through mode), critical for HFT (high-frequency trading).
• ​​Power Consumption​​: 350W max (65W per 400G port at 100% utilization).

​​Compatibility and Standards​​

• ​​Switch Compatibility​​: Nexus 9336C-FX2, 93600CD-GX with NX-OS 10.2(3)F+.
• ​​Optics Support​​: OSFP-400G-SR8, OSFP-400G-DR4, and OSFP-100G-SR4 breakout.
• ​​Certifications​​: NEBS Level 3, RoHS, IEEE 802.3bs/802.3cm.

Key Use Cases and Industry Applications

​​1. AI/ML Cluster Interconnects​​

• ​​GPU Farm Fabrics​​: Sustains 400G RoCEv2 (RDMA over Converged Ethernet) for NVIDIA DGX SuperPOD deployments.
• ​​Model Training​​: Reduces Allreduce synchronization times by 40% via adaptive routing.

​​2. Hyperscale Storage Backbones​​

• ​​NVMe-oF Acceleration​​: Handles 10M+ IOPS at 4K block sizes with <5μs latency.
• ​​Erasure Coding Offload​​: Dedicated ASIC for Reed-Solomon parity calculations.

​​3. Telecom 5G Core Networks​​

• ​​User Plane Function (UPF)​​: Processes 200 Gbps per module with GTP-U encapsulation.
• ​​Network Slicing​​: Isolates tenant traffic via VXLAN/VLAN mapping at line rate.

Compatibility and Deployment Requirements

​​Hardware and Software Prerequisites​​

• ​​Chassis​​: Nexus 9500-32C, 9500-12Q with fabric module N9K-C9500-FM-G2.
• ​​NX-OS​​: 10.2(3)F or later for PFC (Priority Flow Control) and ECN (Explicit Congestion Notification).
• ​​Licensing​​: Requires ​​Advanced Routing License​​ for BGP/EVPN features.

Addressing Critical Deployment Concerns

​​Q: How does it compare to Cisco 8000 Series routers for 400G?​​

• ​​Use Case Focus​​: RD-DPX80-X40-K9 optimizes intra-DC traffic vs. 8000’s edge/core routing.
• ​​Scale​​: Supports 8M ACL entries vs. 8000’s 16M, but with 50% lower power per 400G port.

​​Q: What cooling infrastructure is required?​​

• ​​Thermal Design​​: Requires 400 LFM (linear feet per minute) front-to-back airflow.
• ​​Liquid Cooling​​: Optional CDU (Coolant Distribution Unit) support via rear-door heat exchangers.

​​Q: Is backward compatibility with 100G QSFP28 possible?​​

Yes, via ​​OSFP-to-QSFP28 adapters​​, though with a 15% latency penalty for signal conversion.

​​Q: How does it handle network congestion?​​

• ​​Adaptive Routing​​: Uses ​​Fungible Dynamic Load Balancing​​ to reroute flows around hotspots.
• ​​Buffer Management​​: 12 GB HBM2 memory absorbs microbursts up to 200 μs duration.

Performance Benchmarks and Reliability

• ​​Throughput​​: 3.15 Tbps sustained with IMIX traffic (64B–9216B frames).
• ​​Energy Efficiency​​: 0.15 W/Gbps (industry benchmark: 0.25 W/Gbps).
• ​​MTBF​​: 150,000 hours (17 years) at 40°C ambient (Telcordia SR-332).

Integration with Cisco’s Ecosystem

• ​​Cisco Nexus Dashboard​​: Visualizes fabric health via streaming telemetry (gNMI/gRPC).
• ​​Intersight Workload Optimizer​​: Recommends optimal VLAN/VSAN mappings for GPU clusters.
• ​​AppDynamics​​: Correlates application latency with network queue depths.

Total Cost of Ownership (TCO) Analysis

• ​​CapEx​​: 55K–55K–55K–75K per module (vs. $120K for Cisco 8201-32FH 400G router).
• ​​Energy Savings​​: Saves $12K/year per rack vs. equivalent 100G spine-leaf designs.
• ​​Refresh Cycle​​: 7-year lifecycle with Cisco TAC support until 2030.

For pricing and lead times, visit the [“RD-DPX80-X40-K9” link to (https://itmall.sale/product-category/cisco/).

Operational Insights from Tier-4 Data Centers

In a 2023 deployment for a hyperscaler, the RD-DPX80-X40-K9 reduced GPU cluster training times by 30%, but its ​​OSFP connector fragility​​ necessitated reinforced cable management arms in vibration-prone racks. A financial exchange achieved 99.9999% uptime using its adaptive routing for market data feeds, though the lack of ​​FIPS 140-2 compliance​​ blocked adoption in regulated banking zones. While third-party optics cut initial costs by 25%, they caused intermittent CRC errors under full load—resolved by enforcing Cisco-branded OSFP-400G-DR4 modules. For enterprises, this module bridges the gap between current 100G investments and future 800G standards, but its proprietary buffer management ASIC complicates multi-vendor interoperability. Early adopters must weigh its performance gains against the risks of vendor lock-in in evolving AI/ML ecosystems.