SOLVED - Only getting 1.5Gbps over 10Gbe connection via iperf3

[xxnumbxx]

I recently added a 10gb NIC to my server. It has two SFP+ ports so I am using one for unraid and the other for a windows VM. They are both connected to a Unifi 10Gbe switch. However when I run iperf I am only getting transfers of 1.5Gbps. If I attempt to pull a file from the server to another computer it reduces the transfer rate from the other computer. I have increased the MTU to 9000 in unraid. And both connections register as 10Gbe via unraid and windows. Any help with this would be appreciated.

 

 

UPDATE:

So, I have tried everything I can think of. Force 10Gbe connection on switch. I have made sure my connection is not bonded. Changed the MTU to 9000. I am on the same network, same subnet. I have enabled tuneable(direct i/o). What is also strange is, the connection is faster with the windows client as the iperf server. When using unraid as the iperf server the connection is about half.

 

 

UPDATE 2:

 

Problem was the VM. I tested via another computer and speeds were fine. I ended up adding a 2nd NIC and just passing through to VM. All good now. It didn't like me passing a single SFP+ port from my primary card. Could just be the model but either way. All good now.

Edited March 25, 2022 by xxnumbxx
update:solved

[Ystebad]

If you are pulling from rust you may be seeing the max transfer speed of the drive. Remember it’s not raid. 
 

did you try a nvme or ssd cache drive transfer?

[xxnumbxx]

1 hour ago, Ystebad said:

If you are pulling from rust you may be seeing the max transfer speed of the drive. Remember it’s not raid. 
 

did you try a nvme or ssd cache drive transfer?

I thought iperf3 caches to memory so the hdd is irrelevant. But I am pulling from an SSD.

Edited March 16, 2022 by xxnumbxx

[JorgeB]

Iperf only tests lan, could be am issue with the NIC, router, cable, etc, sometimes also a problem with the NIC driver or options.

[Jclendineng]

Ill note that it looks like you are using single stream iperf in which case that's normal. Try iperf3 -c server -P8 for 8 streams. Also I would NOT change your MTU that's asking for trouble. 1500 is plenty for 10gb. jumbo Is not needed unless you know what its used for and you need it. Its going to give you trouble down the line. Remember, anything on the network that talks to that needs to have the MTU tuned now and if there is any mismatch you will drop packets. my suggestion is leave it default and save yourself the future problems.