Ethernet Slower Than Wi-Fi on Windows 11 — Duplex, Drivers, and Cable Checks

30 Jul 2026

A wired Ethernet connection should almost always outperform Wi-Fi. It offers lower latency, greater stability and, in most cases, higher sustained speeds.

So when your Windows 11 PC downloads files faster over wireless than it does through a network cable, something isn’t right.

Perhaps you’re paying for a 1 Gbps broadband connection, yet your desktop only reaches 90 Mbps over Ethernet while your laptop on Wi-Fi achieves 600 Mbps. Or maybe file transfers crawl across the office network despite having a direct cable connection.

The good news is that this usually isn’t a hardware failure. More often, it’s caused by an incorrect speed negotiation, a damaged network cable, outdated drivers, switch configuration, or Windows network settings.

This guide explains how to diagnose Ethernet performance issues in the correct order, helping you avoid unnecessary hardware replacements.

Should Ethernet Be Faster Than Wi-Fi?

In almost every business environment, yes.

A Gigabit Ethernet connection provides:

Lower latency
More consistent speeds
Better reliability
Less interference
Stable large file transfers
Better VoIP quality
Improved video conferencing
Reduced packet loss

Wi-Fi has improved dramatically with Wi-Fi 6 and Wi-Fi 7, but wireless networks still share airtime with other nearby devices.

A healthy Gigabit Ethernet connection should generally outperform even an excellent wireless connection for sustained workloads.

If it doesn’t, start with the physical connection.

Step 1: Check the Ethernet Link Speed

Before running speed tests, check what Windows believes the network speed actually is.

Open:

Settings > Network & Internet > Ethernet

Select the connected adapter.

Look for:

Link speed (Receive/Transmit)

You may see:

100 Mbps
1.0 Gbps
2.5 Gbps
5 Gbps
10 Gbps

If a Gigabit network only reports 100 Mbps, you’ve already found an important clue.

The computer and switch have negotiated a slower connection than expected.

Microsoft documents viewing network adapter properties through Windows Settings and Control Panel when troubleshooting wired networking. (support.microsoft.com⁠)

Step 2: Confirm What Your Hardware Supports

Not every device supports Gigabit Ethernet.

Check:

Computer network adapter
Docking station
USB Ethernet adapter
Switch
Router
Patch panel
Wall socket
Cable

For example:

Older USB adapters may only support 100 Mbps.
Older switches may only provide Fast Ethernet.
Cheap docks may contain 100 Mbps controllers.
Some printers still use 100 Mbps ports.

Replacing drivers won’t make 100 Mbps hardware run at Gigabit speeds.

Step 3: Compare Ethernet and Wi-Fi Correctly

Disconnect Wi-Fi completely before testing Ethernet.

Otherwise Windows may:

Use different routes
Prefer Wi-Fi for certain traffic
Maintain active wireless connections
Produce misleading speed results

Run several tests.

Include:

Internet speed
Local file transfers
Network copy speeds
Ping times
Video streaming
Microsoft 365 downloads

Don’t rely on one speed-test result alone.

Step 4: Check the Network Cable

A damaged cable is one of the most common reasons Ethernet falls back to 100 Mbps.

Inspect the cable for:

Sharp bends
Crushed sections
Loose clips
Broken locking tabs
Kinks
Poor termination

Then replace it with a known-good cable.

Use:

Cat5e
Cat6
Cat6a

Avoid very old Cat5 cables.

Microsoft recommends checking or replacing Ethernet cables as an early troubleshooting step for wired connection issues. (support.microsoft.com⁠)

Step 5: Try Another Switch Port

Move the Ethernet cable to another switch or router port.

If the speed immediately increases, the original port may have:

Failed auto-negotiation
Physical damage
Incorrect configuration
Hardware faults

Business switches can also have manually configured speeds that don’t match connected devices.

Step 6: Check Auto-Negotiation and Duplex Settings

This is one of the most misunderstood Ethernet settings.

Open:

Device Manager

Expand:

Network adapters

Double-click the Ethernet adapter.

Open:

Advanced

Look for:

Speed & Duplex

Most modern networks should use:

Auto Negotiation

Windows and the switch automatically agree on:

Speed
Duplex mode

Microsoft recommends leaving auto-negotiation enabled unless a specific network design requires otherwise. (learn.microsoft.com⁠)

What Is Duplex?

Duplex determines whether devices can send and receive data simultaneously.

Common options include:

Half Duplex
Full Duplex

Half Duplex:

Sends or receives
Not both simultaneously

Full Duplex:

Sends and receives simultaneously

Modern Ethernet networks should normally operate in Full Duplex.

When Should You Change Duplex?

Usually, you shouldn’t.

Only consider changing it when:

A managed switch is fixed to a particular speed
A legacy device requires matching settings
Auto-negotiation consistently fails
Manufacturer documentation specifically recommends it

Forcing:

1.0 Gbps Full Duplex

while the switch expects Auto can actually prevent the link from working correctly.

Change duplex only after confirming the switch configuration.

Step 7: Update the Network Driver

Open:

Device Manager

Expand:

Network adapters

Right-click the Ethernet adapter.

Select:

Update driver

You can also download the latest approved driver from:

Dell
HP
Lenovo
Intel
Realtek
Broadcom
ASUS
MSI

Laptop manufacturers often customise drivers for:

Docks
Power management
Wake behaviour
Business security

Manufacturer-approved drivers are usually preferable to generic packages.

Microsoft supports updating network drivers through Device Manager or Windows Update. (support.microsoft.com⁠)

Step 8: Install Optional Driver Updates

Open:

Settings > Windows Update > Advanced options > Optional updates

Look for:

Intel Ethernet
Realtek
Broadcom
Killer Networking
Firmware
Dock updates

Optional updates often include network improvements that are not installed automatically.

Step 9: Roll Back a Recent Driver

If Ethernet performance became worse after a Windows Update:

Open:

Device Manager

Choose:

Roll Back Driver

if available.

Test performance before updating again.

Step 10: Check USB Ethernet Adapters

USB adapters introduce another possible bottleneck.

Confirm whether the adapter supports:

USB 3.x
Gigabit Ethernet
2.5 Gigabit Ethernet

A Gigabit adapter connected to a USB 2.0 port will often be limited by USB bandwidth.

Also avoid connecting through inexpensive USB hubs where possible.

Step 11: Test Without the Dock

If your laptop uses a USB-C or Thunderbolt dock:

Connect Ethernet directly to the laptop if possible.

If performance improves:

Investigate:

Dock firmware
Dock drivers
Dock Ethernet controller
USB-C cable
Thunderbolt software

Dock firmware updates often improve network stability.

Step 12: Disable Energy-Efficient Ethernet Temporarily

Some adapters include:

Energy Efficient Ethernet
Green Ethernet
Power Saving Ethernet

These reduce power consumption.

Occasionally they introduce:

Reduced throughput
Link renegotiation
Wake issues
Higher latency

Temporarily disable these options for testing only.

Step 13: Check Power Management

In Device Manager:

Open the adapter properties.

Select:

Power Management

Temporarily untick:

Allow the computer to turn off this device to save power

Restart Windows.

Retest.

Do not disable power management across every device unnecessarily.

Step 14: Disable VPNs for Testing

VPN software changes network routing.

Disconnect:

Corporate VPN
Third-party VPN
Security proxies

Then compare Ethernet performance again.

Remember to reconnect afterwards if required.

Step 15: Test Local Network Speeds

Internet speed is only one measurement.

Copy a large file between:

NAS
File server
Another PC

If local transfers are also slow:

The issue is probably inside the local network.

If local transfers are fast but internet downloads are slow:

Investigate:

ISP
Router
Firewall
Internet connection

Step 16: Check Windows Network Usage

Open:

Task Manager

Select:

Performance

Then:

Ethernet

Monitor:

Throughput
Utilisation
Link speed

Also check:

CPU usage
Disk usage
Memory pressure

A slow SSD can limit file-copy performance even when the network is healthy.

Step 17: Disable Third-Party Network Software Temporarily

Possible causes include:

VPN clients
Bandwidth managers
Endpoint security
Web filtering
Packet inspection
Traffic shaping
Network monitoring

Disable only for controlled testing.

Do not permanently remove business security software without approval.

Step 18: Update Switch Firmware

Business switches receive firmware updates too.

Updates may improve:

Auto-negotiation
VLAN stability
Performance
Security
Compatibility

Check the switch manufacturer’s release notes.

Step 19: Check Router and Firewall Settings

Review:

QoS rules
Bandwidth limits
Traffic shaping
Port security
Link aggregation
VLAN assignment

Incorrect network configuration can make one wired device slower than every wireless device.

Step 20: Run Windows Network Troubleshooter

Open:

Settings > System > Troubleshoot > Other troubleshooters

Run:

Network and Internet

Although it won’t fix every performance issue, it can detect:

Missing adapters
DHCP problems
Gateway issues
DNS problems

Step 21: Reset the Network Stack

Open Terminal as Administrator.

Run:

netsh winsock reset

Then:

netsh int ip reset

Restart Windows afterwards.

Microsoft documents these commands when repairing Windows networking. (support.microsoft.com⁠)

Step 22: Check Event Viewer

Open:

Event Viewer

Review:

Windows Logs > System

Look for:

Network disconnects
Link renegotiation
Driver errors
Adapter resets

Repeated events around slowdowns can identify an unstable adapter.

Step 23: Test Another Computer

Connect another computer using:

The same cable
Same wall socket
Same switch port

If both machines are slow:

The problem is probably in the network.

If only one machine is affected:

Focus on:

Drivers
Windows
Hardware
Dock

Step 24: Consider Hardware Failure

Persistent slow Ethernet may indicate:

Faulty NIC
Damaged motherboard port
Failed USB adapter
Bad dock
Faulty switch port
Damaged structured cabling

Hardware faults become more likely if:

Link speed changes randomly
The connection repeatedly disconnects
Different drivers make no difference
Multiple operating systems show the same problem

The Best Troubleshooting Order

Work through these checks in sequence:

Check Windows link speed.
Confirm hardware supports Gigabit or faster.
Replace the Ethernet cable.
Try another switch port.
Check Auto Negotiation.
Review Speed & Duplex settings.
Update network drivers.
Install optional Windows driver updates.
Test without the dock.
Disable Energy Efficient Ethernet temporarily.
Review power management.
Test without VPN software.
Copy files across the local network.
Monitor Task Manager performance.
Reset the Windows network stack.
Review Event Viewer.
Test another computer.
Investigate hardware.

Common Mistakes

Avoid:

Forcing Full Duplex without checking the switch
Assuming every Cat5e cable is undamaged
Testing through USB 2.0 adapters
Using outdated dock firmware
Ignoring Windows link speed
Comparing Ethernet and Wi-Fi simultaneously
Updating drivers from unofficial websites
Replacing routers before testing cables
Disabling security software permanently
Assuming broadband is the only bottleneck

How Hamilton Group Can Help

Slow wired networking wastes time, disrupts cloud applications and often points to a hidden infrastructure problem rather than simply a slow internet connection.

Hamilton Group can help with:

Windows 11 network troubleshooting
Ethernet performance optimisation
Driver and firmware management
Structured cabling diagnostics
Business Wi-Fi and wired networking
Managed switch configuration
Microsoft Intune driver deployment
Docking station troubleshooting
Network performance monitoring
Office network upgrades
Business broadband optimisation
Complete IT infrastructure health checks

Whether the issue is a damaged cable, an incorrect duplex setting, outdated drivers or a failing switch, our engineers can quickly identify the root cause and restore your wired network to full performance.

Get Your Wired Network Performing Properly Again

A properly configured Ethernet connection should almost always outperform Wi-Fi. Start with the simple checks—link speed, cables and switch ports—before moving on to duplex settings, drivers and firmware.

If your business is struggling with slow wired networking, call Hamilton Group today on 0330 043 0069 or book a call with one of our experts. We’ll identify the bottleneck and get your network running at the speeds it should.