Poor Wifi Performance - GL-MT6000

I have tested in these wireless devices (or network cards) with the MT6000:
AX200, AX201, iPhone11 Pro, iPhone 15 Pro, Huawei Mate40, iPad Pro 2022.

My test topology:

  1. Private Liber Speedtest:
    Libre Speed Server in the PC -> (2.5G WAN) -> MT6000 -> (WLAN) -> Libre speed webpage in the devices
  2. iperf3 test:
    'iperf3 -s' in the MT6000 -> (WLAN) -> 'iperf3 -c' in the devices

The results of above tests:

  1. All devices work well with the MT6000, CH48, 160MHz, WPA2, others are default.
  2. the Liber speed is more stable and faster than iperf3.

Some screenshots:
MT6000:



Private Liber Server:



iperf3:



Suggestions:

  1. iperf3 requires to enable the multi-transmit mode in some devices like AX201 , other devices did not require. That is weird, unknow even Google. But even enable multi-transmit mode, it is also not enough faster than Libre, about 70% of the Libre.
    iperf3.exe -c 192.168.8.1 -R -P16

  2. Probably some wireless network adapter, the latest driver version is not the best, I have tried to downgrade the driver version during my test, to get the best speed.

  3. Probably something interference around the MT6000.