D-link DIR-842 C3 WiFi 5G low performance with OpenWRT

[Smim0]

Hi,

I flashed D-link DIR-842 with OpenWRT and noticed a slow Wifi 5G speed performance, here are iperf test results between 2 computers one connected via Lan port and the other (macbook pro) connected to Wigi 5G ap.

OpenWrt 22.03.5 r20134-5f15225c1e

command: iperf3 -c 192.168.1.150 -P 5 -t 60

[SUM]   0.00-60.00  sec  1.22 GBytes   175 Mbits/sec  2506             sender
[SUM]   0.00-60.01  sec  1.22 GBytes   175 Mbits/sec                  receiver

command: iperf3 -c 192.168.1.150 -P 5 -t 60 -R

[SUM]   0.00-60.01  sec  1.58 GBytes   227 Mbits/sec                  sender
[SUM]   0.00-60.00  sec  1.58 GBytes   226 Mbits/sec                  receiver

I flashed the router back with FW 3.10 and the results are:

OEM firmware FW:3.10

command: iperf3 -c 192.168.1.150 -P 5 -t 60

[SUM]   0.00-60.00  sec  3.49 GBytes   500 Mbits/sec  622             sender
[SUM]   0.00-60.03  sec  3.48 GBytes   498 Mbits/sec                  receiver

command: iperf3 -c 192.168.1.150 -P 5 -t 60 -R

[SUM]   0.00-60.02  sec  3.75 GBytes   536 Mbits/sec                  sender
[SUM]   0.00-60.00  sec  3.74 GBytes   535 Mbits/sec                  receiver

Is this expected? or something is wrong with the OpenWRT firmware for this device?

Thanks

[4zims]

Have you enabled software flow offloading?

[Smim0]

I get the same results with software offloading, the video talks about wired connection

[SUM]   0.00-60.05  sec  1.66 GBytes   237 Mbits/sec                  sender
[SUM]   0.00-60.00  sec  1.65 GBytes   237 Mbits/sec                  receiver

[maurer]

@Smim0

Is this expected?

Yes. Ofw is usually better in terms of wifi performance than openwrt