OCuLink SFF-8611 4i to PCIe 5.0 x16 eGPU Adapter – External GPU Graphics Card Expansion Board for Mini PC, NUC, ITX and Compatible Notebooks, ATX Power Input, K993G

OCuLink eGPU Adapter – PCIe 5.0 x4 Link with Physical x16 Slot, K993G Series

Product Overview

The AXT-LINK K993G OCuLink to PCIe x16 eGPU Adapter is a high-speed external graphics card expansion solution designed to connect a compatible computer with an external PCIe graphics card through an OCuLink SFF-8611 4i interface.

Featuring an OCuLink SFF-8611 4i male input and a PCIe x16 female graphics card slot, the K993G provides a practical way to extend PCI Express connectivity outside the computer chassis. It is designed for external GPU (eGPU) applications involving compatible Mini PCs, Intel NUC systems, ITX computers, small form factor systems, and notebooks equipped with an appropriate OCuLink PCIe output interface.

The K993G supports PCIe 5.0 x4 connectivity, with a manufacturer-specified maximum signaling rate of 128 Gbps. Although the adapter provides a physical PCIe x16 slot for installing a graphics card, the actual PCIe link operates through an x4 lane configuration.

An integrated 24-pin ATX power input allows the adapter to work with a standard ATX power supply to provide power for the external graphics card expansion setup.

The K993G also features an EMI-shielded flexible cable construction, with available cable lengths of 30 cm and 50 cm. A bracket-equipped configuration is available for users who require additional mounting support.

Key Features of the K993G OCuLink eGPU Adapter

OCuLink SFF-8611 4i to PCIe x16 Interface

The K993G connects an OCuLink SFF-8611 4i host interface to a PCIe x16 female slot for installing a compatible desktop graphics card.

This OCuLink to PCIe x16 adapter is designed to extend the PCIe connection outside the host computer, making it suitable for external GPU expansion applications.

PCIe 5.0 x4 High-Speed Connectivity

The K993G is designed for PCI Express 5.0 x4 connectivity, with a manufacturer-specified maximum signaling rate of 128 Gbps.

The PCIe x16 connector provides the physical slot format for graphics card installation. However, the electrical connection uses four PCIe lanes rather than sixteen lanes.

Actual operating generation and performance depend on the host system, graphics card, BIOS configuration, and complete PCIe signal path.

External GPU Expansion for Compatible Computers

The K993G enables a compatible computer with an OCuLink PCIe output interface to connect to an external PCIe graphics card.

It is suitable for:

• Mini PC external GPU expansion

• Intel NUC eGPU configurations

• ITX desktop external graphics solutions

• Small form factor computer systems

• Compatible notebook external GPU setups

• DIY OCuLink eGPU systems

Host compatibility must be verified before purchasing. A computer must provide an appropriate OCuLink PCIe connection; a standard USB-C or Thunderbolt port alone is not sufficient.

Integrated 24-Pin ATX Power Input

The adapter board includes a 24-pin ATX power input for connection to a standard ATX power supply.

The power supply must be selected according to the power requirements of the installed graphics card and the complete expansion setup.

The K993G is designed for use with standard ATX power supplies. Please verify the required PSU capacity and graphics card power connections before installation.

EMI-Shielded Flexible Cable

The K993G uses a flexible flat-cable construction with full metal shielding, designed to help reduce electromagnetic interference and support high-speed PCIe signal transmission.

The manufacturer specifies a nominal cable thickness of approximately 0.8 mm. The flexible cable supports routing for external GPU installation; avoid sharp folds, excessive pulling and stress at the cable-to-board joints.

30 cm and 50 cm Cable Length Options

The K993G series offers two cable length options:

• 30 cm

• 50 cm

These options provide flexibility for different external graphics card positions and host computer layouts.

The specified cable length refers to the K993G flexible cable section only. It excludes the PCB and connectors.

Optional Mounting Bracket

A bracket-equipped version is available for installations requiring additional mechanical mounting support.

Please select the correct model according to your mounting requirements and confirm the supplied bracket configuration before ordering.

Technical Specifications

Important Bandwidth Note:

The PCIe x16 female connector refers to the physical graphics card slot size. The electrical PCIe connection is PCIe 5.0 x4, not PCIe 5.0 x16. The manufacturer's 128 Gbps figure represents the specified aggregate signaling rate; it should not be interpreted as 128 Gbps of application data throughput.

Available cable lengths:

30 cm

50 cm

Cable length Description:

The cable length of this product is the length of K993G. It does not include the PCB and the connector.

AXT K993G series Part-Number Description:

Q&A:

K993G&K993G-BK7

What external power supply options are available for the AXT K993G?
Only standard ATX power supplies are supported. The power rating should be selected based on the graphics card requirements.

What is the switch on the graphics card dock used for?

Flipping the switch to 1 activates automatic startup, allowing the dock to automatically start and stop with the computer. You don't need to flip the switch when the dock is operating normally. Flipping the switch to 2 forces the dock to start, directly powering the dock. If you are using a third-party host adapter and the dock doesn't start properly when the switch is set to 1, flip the switch to 2 to force the dock to start. To ensure device safety, force the dock to start before starting the computer, and shut it down after shutting down the computer.
How do I read the device indicator light?

The D1 light indicates cable testing. Some third-party cables may cause the D1 light to be off. The D2 light indicates the ATX power supply status. If it's on, it means the ATX power supply is functioning properly. If not, please check that the power switch is on and the cables are properly plugged in. The D3 light may not illuminate when using some AMD graphics cards. The D4 light is normally off and only flashes briefly when turning the computer on and off. Normal operation requires the D2 light to be on and the D4 light to be off. The D1 and D3 lights are for testing purposes only; their off status does not affect normal operation.

Is there any EMI shielding for Cable?
With metal shielding.  The cable uses the latest EMI shielding materials with full cable coverage shielding to prevent the incoming or outgoing of electromagnetic frequencies, minimizing interference and performance degradation, and reducing the weight of the extender.

What is the thickness of the cable? Is it soft? Can it be bent?
The manufacturer specifies approximately 0.8 mm nominal cable thickness. The cable is flexible for routing, but should not be sharply folded or placed under strong mechanical stress. The illustration below displays a 0.96 mm measurement; confirm the supplied cable dimensions before designing a tight-clearance installation.

1. What is the K993G OCuLink eGPU adapter?

The K993G is an OCuLink SFF-8611 4i to PCIe x16 external GPU adapter. It connects a compatible host computer to an external desktop graphics card through an OCuLink PCIe connection.

2. Does the K993G support PCIe 5.0?

Yes. The K993G is designed for PCIe 5.0 x4 connectivity, with a manufacturer-specified maximum signaling rate of 128 Gbps.

3. Why does the K993G have a PCIe x16 slot but only support PCIe x4?

The PCIe x16 connector describes the physical slot size for installing a graphics card. The actual electrical connection uses four PCIe lanes. Therefore, the K993G operates with a PCIe x4 link configuration.

4. Can the K993G be used with a Mini PC?

Yes, provided the Mini PC has a compatible OCuLink PCIe output interface and supports external PCIe device connectivity. Check the exact Mini PC model before purchasing.

5. Is the K993G compatible with Intel NUC systems?

It can be used with compatible NUC systems equipped with the required OCuLink PCIe connection. Compatibility depends on the specific NUC model and its hardware configuration.

6. Does the K993G require an external power supply?

Yes. The adapter provides a 24-pin ATX power input and is designed to work with a standard ATX power supply. Select the power supply according to the graphics card requirements.

7. Does the K993G support hot-swapping?

No. OCuLink does not support hot-swapping in this application. Always power down the system before connecting or disconnecting the OCuLink cable.

8. What cable lengths are available?

The K993G is available with 30 cm and 50 cm cable options. The specified cable length excludes the PCB and connectors.

9. What is the difference between K993G and K993G-BK7?

K993G is the standard adapter configuration. K993G-BK7 is the bracket-equipped version, providing additional mounting support. Please confirm the final model designation with AXT-LINK before ordering.

10. What is the difference between K993G, R29Q, and F4Q?

K993G is the external GPU adapter connecting OCuLink to a PCIe x16 graphics card slot. R29Q converts a PCIe x4 slot to OCuLink SFF-8612, while F4Q converts a compatible M.2 NVMe PCIe interface to OCuLink SFF-8612. They serve different functions in an eGPU connection system.

11. Can I use the K993G with a notebook?

Only if the notebook provides a compatible OCuLink PCIe interface and supports the required external PCIe connection. A standard USB-C or Thunderbolt connection alone does not guarantee compatibility.

12. Can I purchase the K993G in bulk?

Yes. AXT-LINK welcomes wholesale and bulk purchase inquiries. Please provide your required cable length, model configuration, and estimated order quantity.

1.It can support M.2 NVMe interface up to 2280 height and can be cut as needed

2.Using Amphenol Oculink SFF-8612 connector, supports PCIe 5.0 full-speed stable transmission

3.UL certified PCB material, gold finger gold-plated 15µ", good conductivity, can reduce the blue screen problem caused by oxidation and rust resistance increase.

R29Q:

BK7:

Test data:

3DMark Time Spy – Direct Graphics Card Connection

Test platform:7600x + 5070 + Xingu 850W power supply (direct plug)

3DMark Time Spy – K993G + F4Q Setup with External Display

Test platform: 7600x + K993G + F4Q + 5070 + Xingu 850W power supply (using graphics card dock adapter)

Test Results: On the same platform, using the K993G eGPU adapter with an F4Q host adapter, the difference in 3DMARK graphics scores was less than 1%.
When using an external graphics card, it is recommended to connect an HDMI or DP cable to the graphics card to ensure external display output. The manufacturer reports approximately 6% higher graphics performance with the external display in this specific comparison; this is not a guaranteed improvement for other systems.
3DMARK benchmark data for a graphics card dock with an external 5070 and an internal display.

Graphics card dock with external 5070 and external screen 3DMARK running data

Photo:

Please confirm the exact model designation and available cable length combinations before placing an order.

Applications of the OCuLink External GPU Adapter

Mini PC External Graphics Expansion

The K993G can connect a compatible Mini PC with an OCuLink PCIe output to a desktop graphics card installed externally.

It provides an external GPU expansion option for systems with limited internal graphics card installation space.

Intel NUC eGPU Expansion

For compatible Intel NUC models equipped with an appropriate OCuLink PCIe interface, the K993G provides a connection between the host computer and an external PCIe graphics card.

Compatibility varies by NUC model and motherboard configuration.

ITX and Small Form Factor Computers

Compact desktop systems may have limited room for a full-size graphics card or may require an external graphics installation layout.

The K993G allows a compatible ITX or small form factor system to connect to an external GPU through OCuLink.

Notebook External GPU Setup

The K993G may be used with compatible notebook computers that provide an appropriate OCuLink PCIe connection.

Not all notebooks support OCuLink eGPU expansion. Please check the actual host interface and system support before purchasing.

DIY External Graphics Card Dock

The K993G is suitable for DIY eGPU configurations that combine an OCuLink host connection, an external graphics card, and a compatible ATX power supply.

Compatible Accessories and OCuLink Connection Solutions

The K993G functions as the external graphics card adapter at the GPU end of an OCuLink eGPU setup.

Depending on the host computer interface, an additional host-side OCuLink adapter may be required.

R29Q – PCIe 5.0 x4 to OCuLink SFF-8612 Adapter

The R29Q provides a PCIe x4 to OCuLink SFF-8612 female connection. It can be used as a host-side interface solution when a compatible PCIe x4 slot is available.

F4Q – M.2 NVMe to OCuLink SFF-8612 Adapter

The F4Q provides an M.2 NVMe to OCuLink SFF-8612 female connection for compatible M.2 PCIe host systems.

R29Q and F4Q are host-side adapter boards, not built-in components of the K993G. This listing also offers F4Q and R29Q as separate selectable options. Choose the required item carefully; selecting a K993G option does not mean that all adapters shown are included. Contact AXT-LINK to confirm package contents before ordering.

Compatibility and Installation Notes

Before purchasing the K993G OCuLink eGPU adapter, please verify the following:

1. The host computer provides a compatible OCuLink SFF-8611 4i PCIe connection or an appropriate OCuLink host-side adapter.

2. The host system supports external PCIe device connectivity through the selected interface.

3. The graphics card is compatible with a standard PCIe x16 slot.

4. The ATX power supply provides sufficient power for the graphics card.

5. The selected cable length is suitable for the installation distance.

6. The mounting arrangement provides sufficient space for the adapter and graphics card.

Important: OCuLink Does Not Support Hot-Swapping

Do not connect or disconnect the OCuLink cable while the computer or expansion setup is powered on.

Power down the system and disconnect the relevant power sources before connecting or removing the OCuLink cable.

ATX Power Supply Requirement

The manufacturer specifies standard ATX power supplies for the K993G. Select the PSU according to the graphics card power requirements.

Switch Operation

The K993G provides two switch positions:

• Position 1: Automatic startup mode, allowing the graphics card dock to start and stop with the computer.

• Position 2: Forced startup mode, directly powering the dock.

If automatic startup does not work properly with a third-party host adapter, forced startup may be used according to the manufacturer's instructions.

When using forced startup, start the dock before starting the computer. When shutting down, turn off the computer first and then shut down the dock.

Manufacturer-Reported Performance Testing

The stated 850W PSU belongs to the reported benchmark configuration. Installation photos may show a different PSU and are examples of the physical setup, not a specification of included equipment.

The manufacturer provides 3DMark comparison results using the following test platform:

• AMD Ryzen 5 7600X processor

• NVIDIA GeForce RTX 5070 graphics card

• 850W ATX power supply

• K993G eGPU adapter

• F4Q M.2 NVMe to OCuLink adapter

Under the reported test configuration, the manufacturer states that the difference in 3DMark graphics scores between the direct graphics card connection and the K993G external GPU setup was less than 1%.

These results refer to the specific test platform and benchmark configuration. Actual performance varies with the host computer, GPU, PCIe link configuration, display connection, drivers, and system settings.

For external display output, the manufacturer recommends connecting the monitor directly to the external graphics card through HDMI or DisplayPort.

Why Choose AXT-LINK OCuLink eGPU Solutions?

AXT-LINK focuses on high-speed I/O extension cable and adapter solutions for computer hardware, external graphics expansion, and system integration applications.

The K993G series provides an OCuLink SFF-8611 to PCIe x16 graphics card connection with PCIe 5.0 x4 connectivity, integrated ATX power input, EMI-shielded cable construction, and optional mounting support.

For customers developing external GPU systems, Mini PC graphics expansion solutions, or custom OCuLink eGPU configurations, AXT-LINK provides product information and technical assistance for interface selection, cable length, and compatibility evaluation.

Wholesale Orders and Technical Inquiries

AXT-LINK welcomes inquiries from computer hardware distributors, system integrators, Mini PC manufacturers, PC component suppliers, and wholesale buyers.

For a quotation, please provide:

• Required model: K993G or bracket-equipped version

• Cable length: 30 cm or 50 cm

• Estimated order quantity

• Host computer interface

• Graphics card model or power requirements

• Any specific mounting requirements

Contact AXT-LINK for product specifications, technical assistance, and wholesale quotations.

Contact AXT-LINK

Looking for an OCuLink eGPU adapter with a PCIe 5.0 x4 electrical link and a physical PCIe x16 graphics card slot?

Contact AXT-LINK for product specifications, compatibility information, technical assistance, and wholesale cooperation.

Downloads

Download 24Pin 6 Pairs Flat Cable Specifications (PDF)

This cable specification document is also provided on the manufacturer's K993G product page. It covers 24Pin 6 Pairs flat cable construction and material properties, not the complete adapter assembly or mounting dimensions. The PDF specifies a cable cross-section of 0.82 ± 0.08 mm thick by 12.0 ± 0.50 mm wide. Follow its minimum bending-radius guidance and avoid sharp folds or strong mechanical stress.

Buy AXT-K993G – Select Model and Cable Length