PCIe X16 to 2MCIO 8X Cable

The PCIe X16 to 2*MCIO 8X Cable from TLD Electronic, a China cable factory in Guangdong, is built for servers and high-performance computing. It uses 30AWG wire, a standard PCIe X16 male interface, and two MCIO 8X connectors. Compliant with SFF-TA-1016, it enables point-to-point connections for NVMe storage and GPU cards, meeting PCIe 5.0 demands for signal integrity.

Key Features

PCIe 5.0-Based Bifurcation Architecture

The PCIe X16 slot at the input end of the cable is designed to connect to 16 PCIe lanes provided by a motherboard or expansion card. At the output end, through precise circuit and shielding structures, the lanes are evenly divided into two independent 8-lane groups, each corresponding to one MCIO 8X connector. This bifurcation is electrically fully transparent and supports standard PCIe link negotiation and splitting functions (requires motherboard BIOS or CPU support for PCIe bifurcation, typically x16 can be split into x8+x8 mode). Each MCIO 8X interface can provide up to PCIe 5.0 x8 bandwidth (approximately 64 GB/s unidirectional, 128 GB/s bidirectional), sufficient to meet the needs of high-end GPUs, EDSFF drives, or smart NICs.

PCIe 5.0 High-Speed Transmission Support

The cable uses high-frequency copper materials (silver-plated copper conductors and low-loss dielectric), combined with a precision dual-coaxial structure, enabling stable transmission of 32 GT/s signals (PCIe 5.0 base rate) over distances of 0.5–1.0 meters. The excellent shielding design effectively suppresses adjacent crosstalk and external electromagnetic interference, ensuring a bit error rate below 1e-12. Additionally, the cable is designed with headroom for PCIe 6.0 upgrades and can also be compatible with future higher speeds in short-distance use.

Compact and Flexible Interface Layout

The MCIO 8X connector itself features extremely high pin density (typically 38 pins, including 8 differential pairs and auxiliary signals), occupying far less PCB space than traditional x8 connectors. The two MCIO 8X interfaces can be independently arranged at the cable ends, facilitating connection to devices at different physical locations (e.g., two separate GPUs or two E1.S drives). The cable assembly supports straight-exit or side-exit designs, avoiding interference with VR heatsinks and fan airflow on the motherboard, helping to improve internal server space utilization.

Reliable Locking and Shielding

Both end connectors feature robust locking mechanisms: the PCIe X16 slot end retains standard clips or locking tabs to prevent loosening under vibration; the MCIO 8X end uses micro latches with stable locking force and convenient one-handed insertion/removal. The exterior is typically wrapped with wear-resistant PVC or low-smoke halogen-free jacket, while internal wire pairs use individual aluminum foil shielding plus overall braided shielding, ensuring overall crosstalk resistance superior to similar adapter solutions.

Specifications

Electrical and Signal Parameters
Transmission Protocol: PCIe 5.0 (backward compatible with PCIe 4.0/3.0/2.0/1.0)

Output Rate: 32 GT/s (per lane), compliant with PCIe 5.0 specification

Lane Configuration: Input PCIe X16 (16 transmit/receive differential pairs), output two independent PCIe X8 (each MCIO 8X interface contains 8 differential signal pairs)

Impedance Control: 85 ± 5Ω (matching PCIe standard)

Physical and Mechanical Parameters

Material: High-frequency copper

Slot Specification: PCIe X16 (male, standard keying, compatible with all PCIe slots)

Output Interface: Two MCIO 8X connectors

Wire Gauge: 30 AWG

Cable Length: OEM customized (common lengths 0.3 m, 0.5 m, 0.8 m, determined by internal server routing requirements)

Compatible Devices
Primary Compatible Devices: Graphics cards supporting PCIe X8 interfaces, including but not limited to NVIDIA A16, A40, RTX 6000 Ada, and AMD data center GPUs in x8 operating mode. Through MCIO 8X to graphics card PCIe gold finger adapter cards, single or multiple graphics cards can be driven (requires motherboard bifurcation configuration).

Other Compatible Devices: NVMe SSDs (U.2, E1.S, E3.S form factors), smart NICs (e.g., Mellanox ConnectX-6), FPGA accelerator cards, and RAID cards.

Typical Application Scenarios

Dual GPU Direct Connection Configuration

In a computing node with only a single PCIe X16 slot (e.g., a 1U server or compact workstation), insert this cable and connect the other end to two MCIO 8X to PCIe X8 adapter cards to drive two high-performance graphics cards, enabling parallel processing for AI inference or graphics rendering tasks without the need for expensive motherboard PCIe bifurcation cards.

Storage Server Lane Expansion

A single PCIe X16 slot on the motherboard connects via this cable to two NVMe backplanes (each supporting x8 bandwidth), respectively mounting 2–4 U.2 SSDs to increase storage density. Due to the compactness of the MCIO interface, backplane design can be positioned closer to the drive trays, shortening high-speed signal paths.

Multi-Node Flexible Interconnection

In OCP open racks, compute nodes route two MCIO 8X signals to adjacent storage nodes or accelerator nodes via the PCIe X16 interface and this cable, utilizing PCIe P2P transmission capabilities to reduce CPU load.

Testing and Validation Platforms

Hardware engineers use this cable to split a PCIe X16 slot on a main test board into two x8 channels, connecting two logic analyzers or protocol analyzers respectively, facilitating simultaneous debugging of two independent signal paths.

Summary

The PCIe X16 to 2*MCIO 8X high-speed bifurcation cable is an ideal solution for flexible conversion from "single-wide channels" to "dual narrow channels" inside high-performance servers. It fully leverages the advantages of the MCIO interface in high density and low loss. Combined with 30 AWG high-frequency copper materials and rigorous impedance control, it maintains excellent signal integrity even at PCIe 5.0 speeds. Whether providing a streamlined interconnect path for dual-GPU systems or efficiently splitting bandwidth in storage servers, this cable helps system designers break through space and lane-count limitations without sacrificing reliability.

FAQ

1. What is this cable used for?

It splits a single PCIe x16 slot into two independent PCIe x8 links via two MCIO 8X connectors, allowing you to connect two GPUs, NVMe SSDs, or other high-speed devices from one x16 slot.

2. Does my system support PCIe bifurcation?

Yes, but your motherboard BIOS or CPU must support x16 bifurcation (usually x8+x8 mode). Without it, the cable will not split the lanes properly.

3. What PCIe version does this cable support?

It is designed for PCIe 5.0 (32 GT/s per lane) and is backward compatible with PCIe 4.0, 3.0, 2.0, and 1.0.

4. What devices can I connect to the MCIO 8X ends?

You can connect GPUs, NVMe SSDs (U.2, E1.S, E3.S), smart NICs, FPGA cards, and RAID cards—provided you use the appropriate MCIO-to-device adapter.

5. What lengths are available?

Standard lengths are 0.3 m, 0.5 m, and 0.8 m, but OEM custom lengths are available to fit your server or workstation layout.

Contact TLD for Wholesale and OEM SAS Cables

TLD supplies PCIe X16 to 2*MCIO 8X Cable for distributors, e-commerce sellers, AV suppliers, and project buyers.

For product samples, OEM requirements, customised packaging, or wholesale orders, contact TLD to confirm the required configuration and quotation.

TLD — HDMI, USB, SAS and AV Cable Manufacturer in Guangdong, China.