Is Netgear R7800 really this slow?

The max wired WAN to LAN speed I get is 50Mb (bits) using openwrt 18.06.1.
My old Buffalo router that's 6 years old and cost less than 1/3 the price gets 250Mb.
I have AT&T gigabit internet and get 930Mb when I just plug straight into their router.

What speeds should I really expect?
This 50Mb I get is straight after install. Fiddling with anything like offload doesn't make any difference. I've tried swapping cables and, obviously, wireless isn't any faster than wired.

While I don't have the r7800, but the very similar nbg6817, it is working fine -and with lots of performance to spare- with 100/40 MBit/s (PPPoE) for me; as-is and without flow-offloading enabled, ipq8065 should be fine for 350-400 MBit/s.

Last I tested I got more than 50mbps even on wireless, although I haven't moved to 18.x yet.

You should probably try @hnyman's build or trunk

From what I understand WIFI is currently a bit wonky due to the change of driver.

Are you sure your connection is not 100baseT half-duplex.

you can check Luci network->switch page or from ssh using swconfig command

# swconfig dev switch0 show | grep link
	blinkrate: 0
	link: port:0 link:down
	link: port:1 link:up speed:100baseT full-duplex 
	link: port:2 link:up speed:100baseT full-duplex txflow rxflow 
	link: port:3 link:up speed:100baseT full-duplex txflow rxflow 
	link: port:4 link:down
	link: port:5 link:up speed:1000baseT full-duplex txflow rxflow auto

Aha - I think the issue is my AT&T router. By changing the MAC address of the WAN interface on the R7800, I'm up to 650Mb!