Iperf results differ between server and client

TrueNAS General
1

I have a Mac Studio with a 10gig nic. I notice when I write to an SMB share on TrueNAS Scale. I get the full 10gig speeds. However when I copy a file from the same share to my Mac, it only copies at around 1 gig.

I tested iperf with TruesNAS being the server and the Mac as the client and again get the full 10gig speed.

When I swap it around to the Mac Studio as the server and TruesNAS as the client, I only get 1gig. Similar to the SMB share speed.

I have swapped cables, ports on the switch and even PCI slots. Nothing makes a difference. These are the only 10gig computers I have. I did test with a window laptop and this maxed out at 1 gig each way due to a 1gig nic.

Any ideas?

Thanks,
James

2

You need to check what the network adapters on the NAS and the Mac say about their negotiated speeds.

3

Thank you for getting back to me. Both the NAS and the Mac are set to 10gig.

4

UPDATE

After changing to a a different NIC the results were just the same. I then realised there was one cable I did not test. Replaced that DAC with another and the issue was resolved.

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