So I bought a used Netgear R7800 on ebay to replace my Archer C7.
Ethernet works great, I get 400Mbps (which is the limit of my ISP) and <1ms ping to the router.
2.4GHz Wifi is okay (pinging the router from my laptop):
ping -c 20 192.168.1.1
PING 192.168.1.1 (192.168.1.1) 56(84) bytes of data.
64 bytes from 192.168.1.1: icmp_seq=1 ttl=64 time=8.84 ms
64 bytes from 192.168.1.1: icmp_seq=2 ttl=64 time=32.6 ms
64 bytes from 192.168.1.1: icmp_seq=3 ttl=64 time=57.9 ms
64 bytes from 192.168.1.1: icmp_seq=4 ttl=64 time=1.26 ms
64 bytes from 192.168.1.1: icmp_seq=5 ttl=64 time=5.17 ms
64 bytes from 192.168.1.1: icmp_seq=6 ttl=64 time=1.41 ms
64 bytes from 192.168.1.1: icmp_seq=7 ttl=64 time=4.24 ms
64 bytes from 192.168.1.1: icmp_seq=8 ttl=64 time=20.9 ms
64 bytes from 192.168.1.1: icmp_seq=9 ttl=64 time=1.42 ms
64 bytes from 192.168.1.1: icmp_seq=10 ttl=64 time=12.1 ms
64 bytes from 192.168.1.1: icmp_seq=11 ttl=64 time=1.50 ms
64 bytes from 192.168.1.1: icmp_seq=12 ttl=64 time=37.5 ms
64 bytes from 192.168.1.1: icmp_seq=13 ttl=64 time=79.9 ms
64 bytes from 192.168.1.1: icmp_seq=14 ttl=64 time=103 ms
64 bytes from 192.168.1.1: icmp_seq=15 ttl=64 time=1.80 ms
64 bytes from 192.168.1.1: icmp_seq=16 ttl=64 time=2.38 ms
64 bytes from 192.168.1.1: icmp_seq=17 ttl=64 time=2.00 ms
64 bytes from 192.168.1.1: icmp_seq=18 ttl=64 time=15.2 ms
64 bytes from 192.168.1.1: icmp_seq=19 ttl=64 time=73.4 ms
64 bytes from 192.168.1.1: icmp_seq=20 ttl=64 time=35.8 ms
--- 192.168.1.1 ping statistics ---
20 packets transmitted, 20 received, 0% packet loss, time 19025ms
rtt min/avg/max/mdev = 1.257/24.928/103.175/30.044 ms
5GHz wifi performance is terrible:
root@laptop:~$ ping -c 20 192.168.1.1
PING 192.168.1.1 (192.168.1.1) 56(84) bytes of data.
64 bytes from 192.168.1.1: icmp_seq=1 ttl=64 time=88.0 ms
64 bytes from 192.168.1.1: icmp_seq=2 ttl=64 time=111 ms
64 bytes from 192.168.1.1: icmp_seq=3 ttl=64 time=3.06 ms
64 bytes from 192.168.1.1: icmp_seq=4 ttl=64 time=7.66 ms
64 bytes from 192.168.1.1: icmp_seq=5 ttl=64 time=1.11 ms
64 bytes from 192.168.1.1: icmp_seq=6 ttl=64 time=1.13 ms
64 bytes from 192.168.1.1: icmp_seq=7 ttl=64 time=2.04 ms
64 bytes from 192.168.1.1: icmp_seq=8 ttl=64 time=1.25 ms
64 bytes from 192.168.1.1: icmp_seq=9 ttl=64 time=1.82 ms
64 bytes from 192.168.1.1: icmp_seq=10 ttl=64 time=97.1 ms
64 bytes from 192.168.1.1: icmp_seq=11 ttl=64 time=111 ms
64 bytes from 192.168.1.1: icmp_seq=12 ttl=64 time=1.04 ms
64 bytes from 192.168.1.1: icmp_seq=13 ttl=64 time=1.67 ms
64 bytes from 192.168.1.1: icmp_seq=14 ttl=64 time=2.01 ms
64 bytes from 192.168.1.1: icmp_seq=15 ttl=64 time=1.61 ms
64 bytes from 192.168.1.1: icmp_seq=16 ttl=64 time=17.6 ms
64 bytes from 192.168.1.1: icmp_seq=17 ttl=64 time=40.2 ms
64 bytes from 192.168.1.1: icmp_seq=18 ttl=64 time=1.95 ms
64 bytes from 192.168.1.1: icmp_seq=19 ttl=64 time=1.23 ms
64 bytes from 192.168.1.1: icmp_seq=20 ttl=64 time=109 ms
--- 192.168.1.1 ping statistics ---
20 packets transmitted, 20 received, 0% packet loss, time 19026ms
rtt min/avg/max/mdev = 1.043/30.084/111.469/43.397 ms
This is with stock firmware (OpenWrt 19.07.7 r11306-c4a6851c72), both Wifi channels on auto, no encryption.
For comparison here's the ping to my Archer C7 (5GHz):
root@laptop:~# ping 192.168.1.2
PING 192.168.1.2 (192.168.1.2) 56(84) bytes of data.
64 bytes from 192.168.1.2: icmp_seq=1 ttl=64 time=2.31 ms
64 bytes from 192.168.1.2: icmp_seq=2 ttl=64 time=0.753 ms
64 bytes from 192.168.1.2: icmp_seq=3 ttl=64 time=7.67 ms
64 bytes from 192.168.1.2: icmp_seq=4 ttl=64 time=0.769 ms
64 bytes from 192.168.1.2: icmp_seq=5 ttl=64 time=1.06 ms
64 bytes from 192.168.1.2: icmp_seq=6 ttl=64 time=0.771 ms
64 bytes from 192.168.1.2: icmp_seq=7 ttl=64 time=9.45 ms
64 bytes from 192.168.1.2: icmp_seq=8 ttl=64 time=31.7 ms
64 bytes from 192.168.1.2: icmp_seq=9 ttl=64 time=53.9 ms
64 bytes from 192.168.1.2: icmp_seq=10 ttl=64 time=0.771 ms
64 bytes from 192.168.1.2: icmp_seq=11 ttl=64 time=88.5 ms
64 bytes from 192.168.1.2: icmp_seq=12 ttl=64 time=97.2 ms
64 bytes from 192.168.1.2: icmp_seq=13 ttl=64 time=0.749 ms
64 bytes from 192.168.1.2: icmp_seq=14 ttl=64 time=0.687 ms
64 bytes from 192.168.1.2: icmp_seq=15 ttl=64 time=0.800 ms
64 bytes from 192.168.1.2: icmp_seq=16 ttl=64 time=0.748 ms
64 bytes from 192.168.1.2: icmp_seq=17 ttl=64 time=0.761 ms
64 bytes from 192.168.1.2: icmp_seq=18 ttl=64 time=0.676 ms
64 bytes from 192.168.1.2: icmp_seq=19 ttl=64 time=0.770 ms
64 bytes from 192.168.1.2: icmp_seq=20 ttl=64 time=0.755 ms
64 bytes from 192.168.1.2: icmp_seq=21 ttl=64 time=0.782 ms
64 bytes from 192.168.1.2: icmp_seq=22 ttl=64 time=0.745 ms
^C
--- 192.168.1.2 ping statistics ---
22 packets transmitted, 22 received, 0% packet loss, time 21295ms
rtt min/avg/max/mdev = 0.676/13.736/97.176/27.951 ms
on your laptops do check you power management settings
I'd just put them to high performance while testing
& do check the driver versions
antivirus & firewalls all so change things
wlo1 IEEE 802.11 ESSID:"OpenWrtLegacy"
Mode:Managed Frequency:2.437 GHz Access Point: B0:B9:8A:73:78:31
Bit Rate=144.4 Mb/s Tx-Power=22 dBm
Retry short limit:7 RTS thr:off Fragment thr:off
Power Management:off
Link Quality=70/70 Signal level=-16 dBm
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:0 Invalid misc:818 Missed beacon:0
I think there's something wrong with my laptop through (Dell Latitude 7400 running Ubuntu 20.04). Tried a different one (Thinkpad T490s, running Fedora 33) without issues.
I tried upgrading to Ubuntu 20.10 but that didn't make a difference.
But the issue with 5Ghz is still there and seems actually worse:
64 bytes from 192.168.1.1: icmp_seq=327 ttl=64 time=1938 ms
64 bytes from 192.168.1.1: icmp_seq=328 ttl=64 time=934 ms
64 bytes from 192.168.1.1: icmp_seq=329 ttl=64 time=1.42 ms
64 bytes from 192.168.1.1: icmp_seq=330 ttl=64 time=115 ms
64 bytes from 192.168.1.1: icmp_seq=331 ttl=64 time=1.70 ms
64 bytes from 192.168.1.1: icmp_seq=332 ttl=64 time=1.58 ms
no answer yet for icmp_seq=333
no answer yet for icmp_seq=334
no answer yet for icmp_seq=335
no answer yet for icmp_seq=336
no answer yet for icmp_seq=337
no answer yet for icmp_seq=338
no answer yet for icmp_seq=339
no answer yet for icmp_seq=340
no answer yet for icmp_seq=341
64 bytes from 192.168.1.1: icmp_seq=333 ttl=64 time=9680 ms
64 bytes from 192.168.1.1: icmp_seq=334 ttl=64 time=8673 ms
64 bytes from 192.168.1.1: icmp_seq=335 ttl=64 time=7653 ms
64 bytes from 192.168.1.1: icmp_seq=336 ttl=64 time=6631 ms
64 bytes from 192.168.1.1: icmp_seq=337 ttl=64 time=5604 ms
64 bytes from 192.168.1.1: icmp_seq=338 ttl=64 time=4582 ms
64 bytes from 192.168.1.1: icmp_seq=339 ttl=64 time=3563 ms
64 bytes from 192.168.1.1: icmp_seq=340 ttl=64 time=2543 ms
64 bytes from 192.168.1.1: icmp_seq=341 ttl=64 time=1515 ms
64 bytes from 192.168.1.1: icmp_seq=342 ttl=64 time=491 ms
64 bytes from 192.168.1.1: icmp_seq=343 ttl=64 time=4.75 ms
64 bytes from 192.168.1.1: icmp_seq=344 ttl=64 time=2.05 ms
64 bytes from 192.168.1.1: icmp_seq=345 ttl=64 time=1.86 ms
64 bytes from 192.168.1.1: icmp_seq=346 ttl=64 time=904 ms
64 bytes from 192.168.1.1: icmp_seq=347 ttl=64 time=891 ms
Not the answer you’ll like, but WiFi is a shared medium, and you therefore are subject to other people using the same wavelengths, and interference.
I also have an r7800 and at times 2.4 bands are better, other times 5ghz is better. I ended up making the ssid different so I could choose which radio I’m connecting to at any given time
Some laptop WiFi devices are better than others . Some also have better drivers than others. Make sure your client devices are all upgraded to latest driver versions.
Also make sure to stay within common channel allocations (ch 3, 6 or 11, see wikipedia for 5 GHz), as only those are independent channels; partial overlap is worse than fully overlapping BSSIDs.