Slow network traffic out of unraid

Hi,

I am stumped on this one.

I have  unraid 6.9.2 running on amd 5800x, rhel 7 5900x talking to new 10gb switch - mikrotik crs309 (in SWOS) via 10gb spf+ mellanox connectx3 cards. Everything else is old 1gb nics and cat5e.

The crs309 talks to my home gateway via 1gb. On the other side i have a switch with old 1gb cable to win10 pc.

Mikrotik and Connectx3 cards are at latest firmware update level.

My problem is plex on unraid is really low network speed to win10 so i have to view movies in 720p.

Iperf3 says the same thing.

Iperf3 from win10 to rhel7 or unraid box is ok.

Iperf3 from rhel7 to win10 box is ok (avg 5 mbits/sec)

Iperf3 from win10 to unraid or rhel7 is ok.

Iperf3 from rhel7 to unraid is fine as is the other way round.

But iperf3 from unraid to win10 sucks.

root@Tower:~# iperf3 -c 10.2.1.12
Connecting to host 10.2.1.12, port 5201
[  5] local 10.2.1.57 port 58770 connected to 10.2.1.12 port 5201
[ ID] Interval           Transfer     Bitrate         Retr  Cwnd
[  5]   0.00-1.00   sec   421 KBytes  3.45 Mbits/sec   23   28.5 KBytes       
[  5]   1.00-2.00   sec  0.00 Bytes  0.00 bits/sec   12   15.7 KBytes       
[  5]   2.00-3.00   sec   188 KBytes  1.54 Mbits/sec    2   59.9 KBytes       
[  5]   3.00-4.00   sec  0.00 Bytes  0.00 bits/sec    0   59.9 KBytes       
[  5]   4.00-5.00   sec  0.00 Bytes  0.00 bits/sec   13   17.1 KBytes       
[  5]   5.00-6.00   sec  0.00 Bytes  0.00 bits/sec    0   17.1 KBytes       
[  5]   6.00-7.00   sec  0.00 Bytes  0.00 bits/sec    0   17.1 KBytes       
[  5]   7.00-8.00   sec  0.00 Bytes  0.00 bits/sec   14   18.5 KBytes       
[  5]   8.00-9.00   sec  0.00 Bytes  0.00 bits/sec    0   18.5 KBytes       
[  5]   9.00-10.00  sec  0.00 Bytes  0.00 bits/sec    0   18.5 KBytes       
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-10.00  sec   609 KBytes   499 Kbits/sec   64             sender
[  5]   0.00-10.00  sec   113 KBytes  92.3 Kbits/sec                  receiver

iperf Done.
 

So thats what Plex is complaining about i believe.

I swapped slots in mikrotik switch to see if the slot was crook and nothing changed.

I swapped spf3 cables from unraid to rhel7 to see if a cable was crook and nothing changed.

I tried tips and tweeks options with out any joy.