Fusion File Share Server performance of Windows 11 lower than previous operating systems
Symptom
When connecting to a Fusion File Share Server from Windows 10, Windows Server 2022, or previous operating systems, you see expected performance that matches your storage and network capabilities. But when connecting a new Windows 11 or Windows Server 2025 client to the exact same Fusion File Share Server and running the same workload, performance drops significantly.
Cause
Windows 11 24H2 and Windows Server 2025 shipped in Autumn of 2024 and changed their default SMB signing security setting to always require by default; this was a change from the past 30 years of Windows. SMB signing degrades performance – this is expected.
Control SMB signing behavior | Microsoft Learn
SMB security hardening in Windows Server 2025 & Windows 11 | Microsoft Community Hub
Solution
For maximum performance, disable SMB signing on the Windows client: Disable SMB signing | Microsoft Learn. No reboot is required but you will need to disconnect and reconnect to the SMB server. No change is necessary in the Fusion File Share Server configuration.
SMB signing brings increased security to Windows clients, preventing relay and tampering attacks; evaluate your threat model to consider performance versus security before disabling signing. Tuxera is also working to improve Fusion File Share Server's signing performance in the future to minimize its impact.