Belkin RT3200: Poor wifi throughput from my linux machine BCM43228 and MT7610U

Hi list,

I'm happy with my router, a Belkin RT3200, onto which I installed openwrt. I have it set for WPA2-PSK authentication.

Using 5 GHz radio, my wife's iMac gets good speed to our ISP:

233.8 Mbps down
13.6 Mbps up.

RX/TX rate samples reported by luci admin/network/wireless page:

216.1 Mbit/s, 80 MHz, HE-MCS 4, HE-NSS 1
612.5 Mbit/s, 80 MHz, HE-MCS 6, HE-NSS 2, HE-GI 1

6.0 Mbit/s, 80 MHz
612.5 Mbit/s, 80 MHz, HE-MCS 6, HE-NSS 2, HE-GI 1

However, my little fanless desktop with this adapter does poorly.

02:00.0 Network controller: Broadcom Inc. and subsidiaries BCM43228 802.11a/b/g/n

At 5 GHz:

20.5 Mbps down
4.1 Mbps up

At 2.5 GHz:

25.1 Mbps down
16 Mbps up

luci:

130.0 Mbit/s, 20 MHz, MCS 15
86.7 Mbit/s, 20 MHz, MCS 12, Short GI

78.0 Mbit/s, 20 MHz, MCS 12
78.0 Mbit/s, 20 MHz, MCS 12

My next try, Panda wireless USB dongle model PAU0A with the MT7610U chip. It connected only at 2.5 GHz. I think it's ironic that this MediaTek wifi adapter connects so poorly to the MediaTek router.

Bus 001 Device 002: ID 0e8d:7610 MediaTek Inc. WiFi

4.7 Mbps down
9.2 Mbps up

I guess I can live with the previous combination, but it rankles me that the download speed is an order of magnitude below the iMac.

Could it be a limitation of my motherboard that affects both PCI and USB? Seems unlikely to me.

Core i7-8565U 1.80 GHz, MAX 4.60 GHz, 4 Cores. 16GB DDR4

Are people getting good throughput with these hardware combinations?
Are there specific wireless parameters I should be looking at?

I'd welcome recommendations for more compatible client wifi adapters.

Thank you

Is USB connected to USB2.0 port? Some of those mt76xxu do not work well in USB3.0 ports.

In my case, it won't connect at either frequency on USB 2.0. Good try tho!

Can you boot openwrt from USB stick and connect to wifi? It looks more like aggressive powersave and never ever tried wifi adaptors.

I see that your Broadcom is connecting at 20MHz channel width, it should be capable to do 5GHz 40MHz channel with 270 or 300Mbps link rate (I don't have this card, but I do have Intel 6205 which is similar and it's able to give > 100Mbps transfer rate), make sure your Linux has proper firmware as most of the Broadcom wifi don't work well under Linux.

For MT7610U, it should also be able to connect 5GHz wifi, did you get any syslog from OpenWrt/client machine to see what's happening? I own 2 different piece of MT7610U dongle and they works perfectly as client/AP on 5GHz.

I have MT7601U dongle and it does about 400 in or 400 out on clean 80Mhz channel.

I don't think it is possible to see 400Mbps on MT7610U other than in a lab environment, it's 1x1 802.11ac so max link rate 433Mbps, also on USB 2.0 bus there will be overhead (the same reason for why 5GbE USB NIC can only give ~3.4Gbps max.) which makes it nearly not possible to achieve. In most of my real world test the MT7610U with same form factor of PAU0A is 230-260Mbps (the best value)

Yes, bidirectional tests do much worse, USB and stuff.

You're suggesting I boot my linux machine with a live ISO to check if it's some issue with my system configuration throttling the CPU?

There are very similar setups working perfectly, thats one thing to rule out (or for you to fix).