Slow NAS transfer speed after Win 10 > 11 clean install

Question

I did a clean install the other day to take me from Windows 10 up to Windows 11 and ever since, my transfer speeds to my Zyxel NAS have been substantially slower (around 17MB/s tops). Previously I would get speeds of at least 80-100 MB/s, so transferring files from my PC to the NAS is taking easily 4x longer compared to before.

Nothing has changed with my PC hardware or network hardware, nor the configuration. I have tried swapping cables as well. The NAS and my PC are both connected via ethernet directly to my router, and the NAS has a static IP address. I'm on a 1000Mbps internet connection and the NAS is mapped via Windows File Explorer. I'm using up to date drivers for ethernet on my PC and the NAS firmware is current.

Any help would be greatly appreciated!

Answer 1

Hello,

Thank you for posting in Microsoft Community forum.

Based on the description, I understand your question is related to Slow NAS transfer speed after Win 10 > 11 clean install.

Potential Causes:

1. Network Adapter Configuration or Drivers:

The network drivers in Windows 11 might be different from those in Windows 10. Even with the latest drivers, there could be compatibility issues.

1. SMB Protocol Version:

Windows 11 may default to using newer versions of the SMB protocol (like SMB 3.x), while your NAS might only support SMB 1.0 or SMB 2.0.

1. TCP/IP Settings:

Windows 11 may have enabled certain network optimization settings (like automatic TCP window size adjustment) that could introduce unnecessary latency or throttling of throughput.

1. Power Management Issues:

Windows 11 might have power-saving settings (such as energy-saving modes) that affect the performance of your network adapter.

1. Firewall or Security Software:

The firewall or security software settings in Windows 11 may differ from Windows 10, potentially impacting file transfer speeds.

1. Network Bandwidth and Other Activities:

Other applications or background tasks running in Windows 11 might be consuming bandwidth, slowing down file transfers.

Solutions:

1. Check Network Adapter Settings:

In Device Manager, check the settings for the network adapter. Ensure it is set to "Full Duplex" and configured to the maximum speed (1000 Mbps).

Update the network adapter drivers to ensure you’re using the latest version.

2. Ensure Correct SMB Protocol Settings:

Check if SMB 1.0 is enabled in Windows 11 (you can do this via Control Panel > Programs > Turn Windows features on or off).

If possible, upgrade the SMB version on the NAS to a newer version (SMB 2.0 or 3.0) to improve compatibility and performance.

3. Adjust TCP/IP Settings:

Disable TCP delay by editing the registry. You can go to the registry editor (regedit), navigate to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters, and modify or add the Tcp1323Opts value to 0.

4. Check Power Management Settings:

In Device Manager, right-click on the network adapter, select "Properties," and go to the "Power Management" tab. Uncheck the "Allow the computer to turn off this device to save power" option.

5. Temporarily Disable Firewall or Security Software:

Temporarily disable the Windows Firewall or any third-party security software to see if it improves transfer speeds. If this helps, you may need to adjust the settings in the security software to allow for higher transfer speeds.

By following these steps, you can troubleshoot and identify the root cause of the slower file transfer speeds. If the issue persists, it might be helpful to check the NAS logs for any errors or warnings that could provide more insights.