board: imxrt1020 evk
wifi module: CMP9010-1-EVB (iw416-based, listed in https://www.nxp.com/products/wireless/wi-fi-plus-bluetooth/iw416-2-4-5-ghz-dual-band-1x1-wi-fi-4-802... )
sdk example: evkmimx1020_wifi_iperf
sdk version: 2.11.0(541 2022-01-14) Manifest version 3.9.0
modification: The only relevant modification is defining WIFI_IW416_BOARD_AW_AM510_USD in app_config.h. Besides, ssid, passphrase, and iperf server ip address are changed.
Host PC: Ubuntu 20.04, iperf 2.0.13 (21 Jan 2019)
According to https://community.nxp.com/t5/Blogs/MCUXpresso-SDK-2-12-0-RT-Platform-NXP-Wireless-Chipset-Release/ba... iw416 easily achieved a tcp throughput of 25~43Mbits (tx) at 2.4GHz or 33~45Mbits/s at 5GHz band. But I can only get 2-4Mbits/s, only 1/10 compared to your test result. I understand imxrt1020 may be slower than imxrt1060, but it's unlikely the cause of such a huge throughput difference.
Is there a good explanation for such a gap, say, not optimal settings in the source code. Or there is no problem in code, I probably got a module with poor performance? Any suggestion will be greatly appreciated.
Following is the output of iperf program. The client chose '3 TCP client dual mode (TX and RX in parallel) right after wifi connected. I also tested both 2.4G and 5GHz bands. 5G band has a slightly higher result. The test board is placed quite close to router, less than 30cm.
```
Client connecting to 10.42.0.55, TCP port 5001
Binding to local address 10.42.0.1
TCP window size: 85.0 KByte (default)
------------------------------------------------------------
[ 6] local 10.42.0.1 port 47043 connected with 10.42.0.55 port 5001
[ 4] 0.0-10.0 sec 2.40 MBytes 2.01 Mbits/sec
[ 6] 0.0-10.1 sec 4.88 MBytes 4.05 Mbits/sec
```
