How to Check Speed and Duplex Settings in Windows 11

Friday, September 11, 2026

How to Check Speed and Duplex Settings in Windows 11

Learn how to check and change Ethernet Speed and Duplex settings in Windows 11 using Device Manager and PowerShell.

If your Ethernet connection is slower than expected, checking the Speed and Duplex setting in Windows 11 can help identify a possible network adapter configuration problem. This setting controls how an Ethernet adapter negotiates its connection with a router, switch, or other network device.

For example, your computer may have a Gigabit Ethernet adapter, but Windows may report a connection speed of only 100 Mbps. The cause could be the Ethernet cable, router or switch port, network adapter driver, or the way the adapter is negotiating its connection.

In this guide, you will learn how to check Speed and Duplex settings in Windows 11, what Auto Negotiation means, how to view the available options, and what to do if your Ethernet connection is stuck at 100 Mbps or another unexpectedly low speed.

What Are Speed and Duplex Settings?

Speed and Duplex is an Ethernet network adapter setting that determines how the adapter communicates with the network device connected to the other end of the Ethernet cable.

The speed represents the negotiated Ethernet connection rate, such as:

10 Mbps
100 Mbps
1.0 Gbps
2.5 Gbps
5 Gbps
10 Gbps

Duplex describes how data can be transmitted across the Ethernet connection.

Modern Ethernet networks generally use Full Duplex, allowing data to be transmitted and received simultaneously. Older networking equipment may support half-duplex operation, but it is uncommon on modern home and office Ethernet networks.

What Is Auto Negotiation?

Auto Negotiation allows the Ethernet adapter and the connected network device to automatically determine compatible connection parameters.

Instead of manually forcing a particular speed, the two devices negotiate the highest compatible mode supported by the connection.

For most modern Ethernet connections, Auto Negotiation should normally be the starting configuration.

If your PC, Ethernet cable, and router or switch all support Gigabit Ethernet, successful negotiation can result in a 1 Gbps link. If something in the physical connection only supports 100 Mbps, the negotiated link may instead operate at 100 Mbps.

Before Changing Speed and Duplex

It is important to understand that changing Speed and Duplex does not automatically make your internet connection faster.

Your maximum Ethernet link speed depends on multiple components:

Ethernet network adapter
Ethernet cable
Router or switch port
Network adapter driver
Configuration of both connected devices

For example, forcing a Gigabit setting on a computer does not turn a 100 Mbps router port into a Gigabit port.

If you want to first determine the current connection speed, see:

How to Check Ethernet Link Speed in Windows 11

Method 1: Check Speed and Duplex Using Device Manager

Device Manager is the most common Windows interface for viewing Speed and Duplex options on an Ethernet adapter.

Press Windows + X.
Select Device Manager.
Expand Network adapters.
Find your Ethernet network adapter.
Right-click the adapter.
Select Properties.
Open the Advanced tab.
Look for Speed & Duplex.

The exact name may vary depending on the network adapter manufacturer and driver.

You might see an entry named:

Speed & Duplex
Speed & Duplex Mode
Link Speed & Duplex

The available options also vary between Ethernet adapters.

How to Identify the Current Speed and Duplex Setting

After selecting the Ethernet adapter's Advanced tab, locate the Speed & Duplex property.

The value displayed in the right-hand section is the current configuration selected for that property.

Depending on the adapter, you may see something similar to:

Auto Negotiation
10 Mbps Full Duplex
100 Mbps Full Duplex
1.0 Gbps Full Duplex
2.5 Gbps Full Duplex

Not every computer will display all of these options. The available choices depend on the Ethernet hardware and installed driver.

Should Speed and Duplex Be Set to Auto Negotiation?

For most modern Ethernet connections, Auto Negotiation is generally the recommended starting point.

It allows the network adapter and the connected router or switch to negotiate a compatible mode rather than forcing one side to use a fixed configuration.

If both sides support Gigabit Ethernet and the physical connection is working correctly, Auto Negotiation should normally be able to establish the appropriate link speed.

Manually selecting 1.0 Gbps Full Duplex should not be treated as a universal fix for a connection that is stuck at 100 Mbps.

If the connection remains at 100 Mbps after changing hardware or configuration, investigate the cable, router port, switch port, and adapter capabilities first.

How to Check Speed and Duplex Without Changing It

If you only want to inspect the configuration, open the Speed & Duplex property and look at the selected value without modifying it.

It is also useful to record the current Ethernet link speed before making any configuration changes.

You can check it with PowerShell:

Get-NetAdapter

For a simpler result:

Get-NetAdapter | Select-Object Name, Status, LinkSpeed

The LinkSpeed value shows the currently reported negotiated link speed.

For example:

Name      Status   LinkSpeed
----      ------   ---------
Ethernet  Up       1 Gbps

This is useful because the Speed & Duplex setting and the actual negotiated link speed are related, but they are not exactly the same piece of information.

How to Check Speed and Duplex With PowerShell

PowerShell can also be used to inspect advanced properties supported by the network adapter.

First, identify the Ethernet adapter:

Get-NetAdapter

Then use:

Get-NetAdapterAdvancedProperty -Name "Ethernet"

If your adapter uses a different name, replace Ethernet with the correct adapter name.

This command can display advanced properties provided by the network adapter driver. The exact properties depend on the manufacturer and driver.

You can search the output for a property related to Speed & Duplex.

How to Change Speed and Duplex in Windows 11

If you have a specific troubleshooting reason for changing the setting, you can modify it through Device Manager.

Open Device Manager.
Expand Network adapters.
Right-click your Ethernet adapter.
Select Properties.
Open the Advanced tab.
Select Speed & Duplex.
Open the Value dropdown.
Select the required option.
Click OK.

Windows may temporarily disconnect the network adapter while the new setting is applied.

Afterward, check the Ethernet link speed again.

Get-NetAdapter | Select-Object Name, Status, LinkSpeed

If the connection becomes unstable or fails to connect, return the setting to the previous configuration, typically Auto Negotiation.

Why Is My Ethernet Stuck at 100 Mbps?

One of the main reasons users investigate Speed and Duplex is an Ethernet connection that remains at 100 Mbps despite having Gigabit-capable hardware.

However, Speed and Duplex is only one possible cause.

1. The Ethernet Cable Is Not Suitable

The cable is one of the first things to check.

A damaged cable or cable with a poor connection can prevent a Gigabit link from being established.

Try replacing the cable with a known-good Ethernet cable and check the link speed again.

2. The Router Port Supports Only 100 Mbps

Some routers and switches have Ethernet ports limited to 100 Mbps.

If your PC is connected to a 100 Mbps port, changing Windows settings cannot make that physical port operate at Gigabit speed.

Check the specifications of the router or switch and make sure the cable is connected to a Gigabit-capable port.

3. The Network Adapter Does Not Support Gigabit Ethernet

Not every Ethernet adapter supports Gigabit speeds.

You can identify the adapter with:

Get-NetAdapter

Then check the hardware specifications from the adapter manufacturer.

4. The Driver Has a Problem

Network adapter drivers control many of the features and settings available to Windows.

If the driver is outdated or malfunctioning, updating or reinstalling it may help resolve network problems.

Device Manager can be used to update, reinstall, or roll back a network adapter driver when the appropriate options are available.

For Wi-Fi adapter driver information, see:

How to Check Wi-Fi Driver Version in Windows 11

5. Auto Negotiation Is Not Working Correctly

In some troubleshooting situations, the connection may not negotiate the expected speed correctly.

Before forcing a manual speed, test another cable and another router or switch port. If the problem persists, compare the adapter's available Speed & Duplex options with the capabilities of the connected network device.

100 Mbps vs 1 Gbps Ethernet

The difference between 100 Mbps and 1 Gbps is significant.

Link Speed	Approximate Maximum Bit Rate	Common Use
10 Mbps	10 megabits/s	Legacy Ethernet
100 Mbps	100 megabits/s	Fast Ethernet
1 Gbps	1,000 megabits/s	Gigabit Ethernet
2.5 Gbps	2,500 megabits/s	Modern high-speed LAN

Actual network throughput is lower than the theoretical link rate because of protocol overhead and other factors.

Also remember that Ethernet link speed does not necessarily equal internet download speed.

Can Changing Speed and Duplex Increase Internet Speed?

Usually, changing Speed and Duplex is not a general method for increasing internet speed.

If your Ethernet adapter already has a 1 Gbps negotiated link and your internet service provides 300 Mbps, forcing another Ethernet setting will not turn the internet connection into a faster service.

However, if the Ethernet link itself is incorrectly negotiating at 100 Mbps when your hardware and connection should support 1 Gbps, troubleshooting the Ethernet configuration may restore the expected local link speed.

How to Troubleshoot Speed and Duplex Problems

Use the following sequence if your Ethernet connection is slower than expected.

Check the current Ethernet link speed.
Inspect the Speed & Duplex setting.
Leave the adapter on Auto Negotiation unless you have a specific reason to change it.
Try another Ethernet cable.
Try another router or switch port.
Check whether the router or switch supports the desired speed.
Check the network adapter driver.
Restart the computer and network equipment when appropriate.
Check the negotiated link speed again.

You can use:

Get-NetAdapter | Select-Object Name, Status, LinkSpeed

to quickly compare the result before and after troubleshooting.

Check Your Network Adapter Information

Before changing advanced settings, it is useful to identify exactly which network adapter Windows is using.

Run:

Get-NetAdapter

You can also use Device Manager:

Press Windows + X.
Select Device Manager.
Expand Network adapters.
Find your Ethernet adapter.
Open Properties to inspect its driver and advanced configuration.

For a broader guide to identifying adapters, see:

How to Check Network Adapter in Windows 11

Check Your IP Address and Default Gateway

If Speed and Duplex appears correct but the network is still having problems, continue troubleshooting the TCP/IP configuration.

Use:

ipconfig /all

This displays information such as the IPv4 address, subnet mask, default gateway, and DNS configuration.

You can learn more here:

How to Check IP Address in Windows 11

You can also inspect the default gateway:

How to Check Default Gateway in Windows 11

If necessary, you can then test connectivity to the gateway using Ping.

How to Ping an IP Address in Windows 11

Frequently Asked Questions

What should Speed and Duplex be set to in Windows 11?

For most modern Ethernet adapters, Auto Negotiation is generally the appropriate starting configuration. It allows the adapter and connected network device to negotiate a compatible speed and duplex mode.

Should I manually set Ethernet to 1 Gbps Full Duplex?

Not necessarily. If Auto Negotiation is working correctly, manually forcing 1 Gbps is usually unnecessary. If the connection is stuck at a lower speed, investigate the cable, router or switch port, adapter capabilities, and driver first.

Why does my Ethernet show 100 Mbps instead of 1 Gbps?

Possible causes include the Ethernet cable, router or switch port, network adapter capabilities, driver problems, or negotiation issues. Test another cable and network port before changing advanced settings.

Does Speed and Duplex affect Wi-Fi?

Speed and Duplex is primarily associated with wired Ethernet network adapters. Wi-Fi uses different wireless standards and configuration mechanisms.

Can I check Speed and Duplex with PowerShell?

Yes. You can use Get-NetAdapterAdvancedProperty to inspect advanced properties exposed by the network adapter driver. The exact properties available depend on the adapter and driver.

What is Full Duplex Ethernet?

Full Duplex allows a network connection to transmit and receive data simultaneously. Modern switched Ethernet networks normally use full-duplex communication.

Related Windows 11 Networking Guides

Conclusion

Checking Speed and Duplex settings in Windows 11 can be useful when troubleshooting Ethernet connections that do not operate at their expected speed. Device Manager provides access to the adapter's advanced properties, while PowerShell can help you inspect adapter information and the current negotiated link speed.

For most modern Ethernet connections, Auto Negotiation is a sensible starting configuration. If your connection is stuck at 100 Mbps instead of 1 Gbps or another expected speed, changing the setting should not be the first troubleshooting step. Check the Ethernet cable, router or switch port, network adapter capabilities, and driver as well.

Once the physical connection and adapter configuration are working correctly, checking the reported link speed gives you a useful baseline for further network troubleshooting.