How to fix slow network speed with Windows 11 to local NAS via Samba / SMB Share

Problem: I replaced my Windows 10 computer with a new Windows 11 one. On W10 I usually see a throughput to my Synology NAS of close to 1 Gbit/sec. On W11 the throughput was ways slower: I only got ~300 Mbit/sec when copying to/from the Samba Share.

Cause: Windows 11 seems to requests SMB signing which seems to impact the throughput “a bit”. More about SMB signing and the differeent options can be found at Microsoft directly:

• Configure SMB Signing with Confidence | Microsoft Community Hub
• Overview of Server Message Block signing – Windows Server | Microsoft Learn

Solution: Disable SMB Signing. I am in a local network, a man-in-the-middle attack is rather unlikely to me. So I prefer the speed over this extra security.

The change can be done in the registry directly:

HKLM\SYSTEM\CurrentControlSet\Services\LanmanWorkstation\Parameters,
add RequireSecuritySignature=0.
MAYBE add the same in HKLM\SYSTEM\CurrentControlSet\Services\LanmanServer\Parameters

If you prefer to do the changes in the Gui, please refer to the following articles:

• Configure SMB Signing with Confidence
• Beheben von SMB-Signaturfehlern für den NAS-Zugriff unter Windows 11 24H2

Or via Powershell: The Article Beheben von SMB-Signaturfehlern für den NAS-Zugriff unter Windows 11 24H2 describes how to change the settings via Powershell:

reg add "HKLM\SYSTEM\CurrentControlSet\Services\LanmanWorkstation\Parameters"/v RequireSecuritySignature /t REG_DWORD /d 0 /f