Slow LAN speeds on RBR850, half of what I got on my RBR50

The WAN (Internet) port on the RBR850 router is a 2.5GB Ethernet port.  When the Orbi Speed Test reports 1.4GB, that is an indication that the link between the cable modem and the router is running at 1.4GB.

My guess is that the computer has an 'ordinary' Gigabit Ethernet adapter.  That means when the computer is connected to anything, the maximum Ethernet link that can be negotiated is 1GB.  In practice, the maximum throughput on a 1GB Ethernet link is slightly less than a full gigabit because of the overhead in Ethernet transmission.  950ish is pretty typical.

I agree entirely, when

• the modem is delivering 1.4G to the router
• the Orbi router port is 1G
• the computer port is 1G

Then the measured speed at the computer should be slightly under 1G ("950ish")  A speed of "half that" is unacceptable. I can think of nothing that would explain how an 850 would produce less speed than a 50.  None.

Fortunately, a new purchase comes with 90 days of "complimentary support" (as opposed to, "you bought it. YOU figure out how to make it work.")  How about registering the new system with Netgear at my.netgear.com and have them explain this?