@Ofloo_ 

Hello,

CAT7 cables, both ends sync at 10GBit however maximum speed over iperf is only 700mbits !?

Well, 700M is too low compared with 10G. Perhaps there is something affected the results, or the switch has an issue.

How you test the speed over iperf, in the default settings and connected with two PCs who have 10G Ethernet ports?

@Yannie 

Both have 2x10G there both on the same switch on one i run iperf -s and the other iperf -c "ipv4 of the one with iperf -s" both are in the same subnet. No router or whatever in between.

enableing jumbo frames and setting this to maximum, setting one of both clients to frame size of 9000

iperf -c 10.13.25.11
------------------------------------------------------------
Client connecting to 10.13.25.11, TCP port 5001
TCP window size:  168 KByte (default)
------------------------------------------------------------
[  3] local 10.13.25.1 port 18467 connected with 10.13.25.11 port 5001
[ ID] Interval       Transfer     Bandwidth
[  3]  0.0-10.0 sec  1.41 GBytes  1.21 Gbits/sec

If i set both to jumbo frames the speed drops back to arround 900mbits

Did diagnostic checks no errors found on any of the ports, .. cables are less then 10m in length. This switch turns out to be a disapointment. Esspecially if you know it costs about 800euro ! 1euro per mbit?

@Ofloo_ 

enableing jumbo frames and setting this to maximum, setting one of both clients to frame size of 9000

iperf -c 10.13.25.11
------------------------------------------------------------
Client connecting to 10.13.25.11, TCP port 5001
TCP window size:  168 KByte (default)
------------------------------------------------------------
[  3] local 10.13.25.1 port 18467 connected with 10.13.25.11 port 5001
[ ID] Interval       Transfer     Bandwidth
[  3]  0.0-10.0 sec  1.41 GBytes  1.21 Gbits/sec

 

If i set both to jumbo frames the speed drops back to arround 900mbits

Did diagnostic checks no errors found on any of the ports, .. cables are less then 10m in length. This switch turns out to be a disapointment. Esspecially if you know it costs about 800euro ! 1euro per mbit?

Hard to tell, not sure if it would be affected by some special settings on the switch, I suggest to factory reset the switch then run the iPerf test again. If both PCs connected to the switch can negotiate to 10G, but iPerf test is still around 1G, contact the TP-Link support for some advice.