PCIe 4.0 x16 Male to x8 Female Extension Cable

The PCIe 4.0 x16 Male to x8 Female Extension Cable is a high-performance passive interconnect solution engineered for 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 x8 interface, supporting a data transfer rate of 16.0 GT/s per lane and delivering a total bandwidth of approximately 15.75 GB/s for the x8 configuration, with backward compatibility to PCIe 3.0/2.0/1.0 devices. 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 in high-speed applications. The passive design addresses form-factor adaptation needs in space-constrained environments such as test benches, compact workstations, or servers, where flexible card placement is critical without sacrificing signal integrity at PCIe 4.0 speeds.

Features

• Form Factor Adaptation: Enables physical and electrical compatibility between PCIe x16 and x8 interfaces, allowing x8 devices (e.g., high-speed network cards or controllers) to be installed in x16 slots while operating at x8 lane speeds .
• PCIe 4.0 Compliance: Supports PCIe 4.0 specifications with a data transfer rate of 16.0 GT/s per lane, leveraging 128b/130b encoding for high-efficiency transmission .
• 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) .
• Passive Design: Requires no external power or active components, relying on high-quality copper conductors and robust construction for plug-and-play operation .
• Durable Construction: Incorporates gold-plated contacts (e.g., min. 0.76µm thickness ) and reinforced housings to withstand mechanical stress in commercial or industrial environments.

Specifications

• Product Model: PCIe 4.0 x16 Male to x8 Female Extension Cable
• Connector A: PCIe 4.0 x16, Male, Edge Connector
• Connector B: PCIe 4.0 x8, Female, Receptacle
• Cable Type: Passive Copper Extension Assembly
• Pinout Configuration: PCIe-compliant, mapping x16 host interface to x8 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 x8 add-on cards (e.g., NICs or accelerators) need installation in x16 slots for space optimization .
• Test and Development Benches: Facilitating hardware validation and signal integrity analysis of x8 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 x8 slots are obstructed by larger components like GPUs or cooling systems.
• Multi-GPU Configurations: Supporting secondary graphics cards or computational accelerators in x8 mode when the primary x16 slot is occupied .