A sudden drop in Wi-Fi speed to 10 Mb/s can be frustrating and is often caused by a combination of hardware and software factors. In this article, we’ll explore the most common causes of this issue and offer concrete, technical solutions.

Understanding Mb/s vs MB/s

Before diving in, it's important to distinguish between the units:

• Mb/s (megabits per second): A common unit of network transmission speed.

• MB/s (megabytes per second): A unit for data volume, where 1 MB = 8 Mb.

If your Wi-Fi is running at 10 Mb/s, the actual data throughput is around 1.25 MB/s, which is below the standard of modern Wi-Fi networks.

Main Causes of Wi-Fi Speed Dropping to 10 Mb/s

1. Incorrect Network Adapter Settings (Full Duplex vs. Half Duplex)
   Your network adapter might be set to a fixed speed of 10 Mb/s or operating in half duplex mode. This can be checked in Windows or using the ethtool command on Linux.

2. Damaged or Low-Quality Ethernet Cable
   If your Wi-Fi router is connected to the network via an Ethernet cable, an outdated or damaged cable (e.g., Cat 3) can force the connection to 10 Mb/s.

3. Insufficient Power Supply to USB Wi-Fi Adapter
   Some USB Wi-Fi adapters switch to low-speed modes when not adequately powered, especially when connected to passive USB hubs. Use direct ports on the motherboard for stable performance.

4. Improper Router or Access Point Settings
   Older routers may have ports limited to 10 Mb/s by default. Also, if the router is set to 802.11b mode, it limits the wireless speed to a maximum of 11 Mb/s.

5. Outdated Network Drivers
   Obsolete or corrupted drivers can lead to incorrect speed detection or operation.

6. Interference in the 2.4 GHz Band
   Heavy congestion in the 2.4 GHz band can significantly reduce your Wi-Fi performance. Switching to a 5 GHz network often resolves this issue.

Additional Factors Affecting Wi-Fi Speed

• Overloaded Home Network
  A large number of connected devices can saturate the network. Disconnect idle devices and enable QoS (Quality of Service) to prioritize critical traffic like video calls or streaming.

• ISP Data Throttling or Limit
  Some internet service providers slow down speeds after a certain data limit. Check your plan’s conditions and consider upgrading to an unlimited plan if needed.

• Weak Wi-Fi Signal
  Physical obstacles (walls, furniture) can weaken the signal. To improve coverage, consider Wi-Fi extenders, mesh systems, or Powerline adapters

How to Diagnose and Fix the Issue

• Check the Network Adapter Status

  In Windows:

  1. Open Control Panel

  2. Go to Network and Internet > Network and Sharing Center > Change adapter settings

  3. Right-click on the relevant adapter and select Status

  If the speed shows 10.0 Mb/s, the issue is confirmed.

• Change Network Card Settings

  Go to the adapter’s advanced settings and set Speed & Duplex to Auto Negotiation or 100 Mb/s Full Duplex.

• Test with a Different Ethernet Cable

  Use a cable rated Cat 5e or higher for full-speed support.

• Switch to 5 GHz Wi-Fi Network

  If your router supports dual-band, connect to the 5 GHz SSID for better performance and less interference.

• Update Firmware and Drivers

  Regular updates to your router’s firmware and network drivers ensure optimal compatibility and performance.

• Try a Different USB Port

  Preferably use a USB 3.0 port directly on the motherboard. Avoid extension cables or passive USB hubs that can limit power delivery and reduce adapter speed.

Don’t Skip a Simple Restart

A basic restart of your router, modem, and computer can often solve temporary issues like IP conflicts or buffer overloads. It’s a simple but frequently overlooked solution—especially if devices have been running non-stop for days.

Change the Wi-Fi Channel

In congested environments (e.g., apartment buildings), try changing the Wi-Fi channel in your router's settings. In the 2.4 GHz band, channels 1, 6, or 11 are ideal. The 5 GHz band offers more non-overlapping channels and better performance.

Temporary Fix: Use a Wired LAN Connection

For critical tasks (video calls, uploading large files, streaming), consider using an Ethernet cable for a direct connection. This provides much greater stability than Wi-Fi, especially in heavily loaded environments.

A Wi-Fi speed drop to 10 Mb/s almost always has a technical cause that can be resolved. Whether it's a configuration issue, faulty hardware, or environmental interference, methodically diagnosing the problem usually leads to a solution. Be sure to check your router settings, update firmware, switch to 5 GHz, or extend your network if needed.

If the issue persists after all these steps, contact your internet service provider—the problem might be on their side, such as a misconfigured line or outdated equipment.