10GbE servers can still copy slowly through file managers
A 10GbE link between an Unraid server and a Windows desktop works at full network speed in testing. iperf3 shows about 9.5Gb/s, so the network connection itself is close to the expected limit. robocopy with the /MT:32 and /J options reaches about 1.7GB/s, which suggests the server, NVMe drives, and 10GbE link can handle high speed transfers.
Standard copying through Windows or Double Commander is much slower and stays around 160MB/s. Unraid has SMB Multichannel turned on, and the uses Exclusive access on a Gen4 NVMe cache pool only. The desktop also has a fast NVMe drive.
The likely is not the hardware, but the software path used by graphical file managers, SMB behavior, settings, or group policy.
Key points
- iperf3 reports about 9.5Gb/s, so the 10GbE link appears healthy.
- robocopy reaches about 1.7GB/s with /MT:32 and /J.
- Windows and Double Commander stay near 160MB/s for the same kind of transfer.
- SMB Multichannel is enabled on Unraid, and the share uses only a Gen4 NVMe cache pool.
- Slow real-world copying can come from the file manager or SMB path even when the network is fast.