PCIe 4.0 x16 Male to x4 Female Down R/A Extension Cable

The PCIe 4.0 x16 Male to x4 Female Down R/A Extension Cable is a high-performance passive interconnect solution engineered for space-constrained systems requiring adaptive connectivity between different PCIe slot sizes while maintaining PCIe 4.0 compliance. This cable converts a larger PCIe x16 slot interface into a smaller PCIe x4 interface, supporting a data transfer rate of 16.0 GT/s per lane and delivering a total bandwidth of approximately 7.88 GB/s for the x4 configuration, with backward compatibility to PCIe 3.0/2.0/1.0 devices . The design incorporates a Down Right-Angle (Down R/A) female connector that optimizes spatial efficiency by directing the cable downward relative to the motherboard plane, reducing mechanical obstruction in low-clearance environments such as 1U/2U servers or compact workstations . Constructed with 85-ohm impedance-matched wiring (e.g., 31 AWG low-loss twin-axial cable as referenced in 3M’s Gen 4.0 extender assemblies) and multi-layer shielding , this cable minimizes signal degradation while addressing mechanical routing challenges in high-density configurations. The passive design addresses both form-factor adaptation and cable routing needs, making it ideal for test benches, data centers, and custom systems where flexible card placement is critical.

Features

• Form Factor Adaptation: Enables physical and electrical compatibility between PCIe x16 and x4 interfaces, allowing x4 devices (e.g., NVMe SSDs or network controllers) to be installed in x16 slots while operating at x4 lane speeds .
• Down Right-Angle Connector Optimization: The Down R/A female connector directs the cable downward relative to the motherboard plane, minimizing vertical profile and preventing interference with adjacent components (e.g., GPUs or cooling systems) in low-profile chassis .
• PCIe 4.0 Compliance: Supports PCIe 4.0 specifications with a data transfer rate of 16.0 GT/s per lane, providing approximately 7.88 GB/s bandwidth for the x4 interface .
• 85-Ohm Impedance Matching: Precisely controlled differential impedance reduces signal reflections and ensures integrity at 16.0 GT/s data rates, critical for PCIe 4.0 applications .
• Enhanced Signal Integrity: Utilizes low-loss twin-axial cables with multi-layer foil and braid shielding to minimize insertion loss, crosstalk, and electromagnetic interference (EMI), ensuring stable performance even in electrically noisy environments .
• Passive Design: Requires no external power or active components, relying on high-quality copper conductors and precise impedance control for reliable operation .
• Durable Construction: Incorporates gold-plated contacts (e.g., min. 0.76µm thickness) and reinforced connector housings to withstand mechanical stress in commercial or industrial environments .

Specifications

• Product Model: PCIe 4.0 x16 Male to x4 Female Down R/A Extension Cable
• Connector A: PCIe 4.0 x16, Male, Edge Connector
• Connector B: PCIe 4.0 x4, Female, Down Right-Angle (Down R/A)
• Cable Type: Passive Copper Extension Assembly
• Pinout Configuration: PCIe-compliant, mapping x16 host interface to x4 device lanes 
• Data Rate Support: Up to 16.0 GT/s (PCIe 4.0) 
• Supported Protocols: PCI Express 4.0/3.0/2.0/1.0
• Impedance: 85 ohms differential (compliant with PCIe 4.0 standards) 
• Wire Gauge: 31 AWG (high-precision copper, typical for PCIe 4.0 low-loss applications) 
• Shielding: Foil and braid for comprehensive EMI protection 
• Cable Length: Standard options: 0.25m, 0.5m (custom lengths up to 1.0m available; longer lengths require validation) 
• Operating Temperature: -40°C to +85°C (industrial grade) 
• Durability: Minimum 500 insertion cycles
• Safety Standards: RoHS compliant

Applications

• High-Density Servers: Deploying in rack-mounted systems (e.g., 1U/2U configurations) where the Down R/A design optimizes cable routing in cramped spaces for x4 add-on cards (e.g., NICs or accelerators) installed in x16 slots .
• Test and Development Benches: Facilitating hardware validation and signal integrity analysis of x4 devices in multi-slot environments, enabling debugging or compatibility testing at PCIe 4.0 speeds .
• Compact Workstations: Enabling flexible component placement in small-form-factor builds where motherboard x4 slots are obstructed by larger components like GPUs or cooling systems .
• Industrial and Embedded Systems: Supporting PCIe expansion in ruggedized equipment where reliable high-speed connections and space-efficient routing are essential .