Hi all,

I'm having an issue where SMB connections to my UnRAID NAS are only around 130 MB/s, even with 2.5G hardware.

Setup:
Win11 Client (Intel X520 DA1 10G PCIe Card)
10G DAC Cable (2,5m)
Switch (4x 2.5G, 2x SFP+)
Ugreen DXP4800 (2x 2.5G) (ZFS Pools for Cache and for HDDs)

SMB Transfer PC (SSD) to Unraid (NVME):

iperf3:

Looks Perfect for 2.5G Setup, so I guess my Hardware is not the Problem here.

SMB settings:


I have already tried:

• Use bigger File (32GB Backupfile)

• Enable Jumbo Frames

• Use direct Disk Share

• Reboot PC / NAS

• Disable Network teaming

• Robocopy with /MT

• Set-SmbServerConfiguration -EnableMultiChannel $true

• Disabled flow control

• Changed PCIe x16 Slot from x2 > x4

• Checked SMBv1 was disabled

• Tried NFS but same slow speed

• Disabled Windows Defender

• Disabled Interrupt Moderation & Rate > Speed jumped to 200 MB/s
  

I have had some luck so far and would really appreciate it if anyone could suggest what the problem for the rest might be.

Edited March 12Mar 12 by Desertwolf
Some success with Interrupt Moderation Setting

I recommend always running iperf with a single stream; multiple streams will not be comparable to a single transfer speed.

3 minutes ago, JorgeB said:

I recommend always running iperf with a single stream; multiple streams will not be comparable to a single transfer speed.

Hi and thanks for your reply.
With single stream I get 1.82 Gbits/sec

That's not line speed, and the closer to the transfer speed you get, meaning the LAN itself is not working optimally, you can try some tweaks or a different NIC, I get around 280MB/s transferring from Windows to my server with 2.5GbE, and iperf gives line speed results with a single stream.