How to Install Realtek RTL8159 Driver on macOS for Higher Ethernet Speed

Applicable Product

Cable Matters 10Gbps USB-C Ethernet Adapter (Model 201496)

Issue

Some macOS computers may use the built-in Apple network driver for the Realtek RTL8159 chipset. Installing the Realtek RTL8159 driver allows the adapter to use the dedicated Realtek driver and helps achieve higher Ethernet performance when connected to compatible network equipment.

Before You Start

• Connect the Cable Matters 201496 adapter to your Mac
• Connect your Mac to the Internet through another connection (Wi-Fi recommended)
• Make sure you have administrator access

Step 1: Download and Install the Realtek Driver

Click here to download the driver.

Open the downloaded Realtek RTL8159 driver package (.pkg). Follow the installation instructions and enter your Mac administrator password when prompted.

Step 2: Confirm Driver Installation

Wait until the installation completes successfully, then close the installer.

Step 3: Launch RTL815xEthernetApp from Applications

Open Finder → Applications and launch RTL815xEthernetApp. The application will guide you through enabling the required driver extension.

Step 4: Allow the Realtek System Extension

Open System Settings → Privacy & Security. Locate the Realtek system software approval message and click Allow.

If you don't see the message, or if you accidentally clicked "OK" or dismissed it, don't worry. You can manually go to System Settings and enable the driver extension in step5.

Step 5: Enable the Realtek Driver Extension

In Driver Extensions, locate RTL815xEthernetApp and enable the extension switch.

Step 6: Restart Your Mac

Restart your Mac to complete the driver installation. Then reconnect the Cable Matters 201496 adapter and check Ethernet performance.

Step 7: Verify Ethernet Adapter Settings & Set Speed to Auto

After restart, go to System Settings → Network → Ethernet. The adapter may appear as "Ethernet Adapter" due to a current driver limitation and may not display the 10Gbps adapter name. This does not affect performance.

Set Configure and Speed to Automatically to allow macOS to negotiate the best available Ethernet speed.

Troubleshooting

• If the driver extension does not appear:
Disconnect the adapter, restart your Mac, reconnect the adapter, and check Privacy & Security settings again.

• If Ethernet speed does not improve:
Verify that your Ethernet cable, router/switch, USB-C port, and network equipment support the expected speed.

Notes

Actual Ethernet speed depends on the adapter, computer hardware, cable quality, network equipment, and test environment.