Wow these results are indeed much faster than I am seeing. My laptop is AC1200 as well I think, and I am testing very close to the router, so it should not be limiting performance.
I have the latest overclocked firmware installed (2020_01_03_1de8f-v0.30.oc) but did not install any of the packages. Should I have irqbalance or something to improve performance? Is there anything obvious I could have misconfigured? I basically followed the guide here, but there were a couple of places where it is not completely clear.
The device does not seem to be overloaded, and I am not running any additional services besides relayd.
If I can improve performance I'd like to buy another to put elsewhere in my house, as I have a lot of machines without modern wifi cards (or wifi at all) and running cat6 around the house is not something I want to do at present.
Sorry, I am a complete noob with this. I will test again this evening and double check my settings. Thanks for your help.
EDIT: I've just been looking again at my settings, and everything looks OK, but the wireless status page shows that my laptop is only connected at 300mbps (n mode, I guess). It is ac capable (Intel Corporation Wireless 8260) but I can't figure out how to force it to use ac, or if there is a driver problem (running linux on the laptop, for what it's worth).
EDIT2: Cannot for the life of me figure out how to get my laptop to connect faster than 300mbps... so I decided to take a different approach and connected with an ethernet cable to my main wifi router to run iperf3 from my laptop to the ea6350v3:
Connecting to host 192.168.1.2, port 5201
[ 4] local 192.168.1.231 port 60278 connected to 192.168.1.2 port 5201
[ ID] Interval Transfer Bandwidth Retr Cwnd
[ 4] 0.00-1.00 sec 60.6 MBytes 508 Mbits/sec 0 983 KBytes
[ 4] 1.00-2.00 sec 68.1 MBytes 571 Mbits/sec 0 983 KBytes
[ 4] 2.00-3.00 sec 68.5 MBytes 575 Mbits/sec 0 983 KBytes
[ 4] 3.00-4.00 sec 68.9 MBytes 578 Mbits/sec 0 983 KBytes
[ 4] 4.00-5.00 sec 69.0 MBytes 579 Mbits/sec 0 983 KBytes
[ 4] 5.00-6.00 sec 68.4 MBytes 574 Mbits/sec 0 983 KBytes
[ 4] 6.00-7.00 sec 69.0 MBytes 579 Mbits/sec 0 983 KBytes
[ 4] 7.00-8.00 sec 68.3 MBytes 573 Mbits/sec 0 983 KBytes
[ 4] 8.00-9.00 sec 68.5 MBytes 574 Mbits/sec 0 983 KBytes
[ 4] 9.00-10.00 sec 65.2 MBytes 547 Mbits/sec 103 757 KBytes
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval Transfer Bandwidth Retr
[ 4] 0.00-10.00 sec 674 MBytes 566 Mbits/sec 103 sender
[ 4] 0.00-10.00 sec 671 MBytes 563 Mbits/sec receiver
Oddly, if I go in the other direction (with my laptop running as iperf3 server) I get less than 10mbps. But I can only assume that is not a problem of the ea6350v3 but something elsewhere.
Anyway, a massive improvement so I think I'll be getting a second ea6350v3 for another room!