eloriseph wrote

I have the same problem. (archer c7 v2, newest firmware here, ipv4 & ipv6 dual stack from the provider)

ISP speed is 400 mbit/s. After restarting the router i get the full speed over nat ~ 400 mbit/s down.
After some time speed drops to ~ 280-300 mbit/s. With hardware nat deactivated the speed is also ~ 280-300 mbit/s.
Could be a hardware nat issue (hardware nat drops -> software nat) ?

How often does the speed drop?
It is important to test if the speed is stable or not when your PC is connected to the modem directly and work for a period of time.

Tony Seaford wrote

How often does the speed drop?
It is important to test if the speed is stable or not when your PC is connected to the modem directly and work for a period of time.

When the PC is connected directly to the modem the speed never drops even after 3 hours it does not drop. (checked with speedtests, http downloads, torrent downloads)

If the PC is connected to the Archer c7 v2, the speed drops after some minutes.
The first speedtest or download shows ~ 400 mbits, then I surf the web for some minutes and the next speedtest or download rate is only 280 mbits.

Three things help to recover the full download speed for some minutes:

- power off / power on the archer
- remove / reattach the wan cable between the archer and the modem
- login to the web page of the archer and release / renew the wan ip address

also I have seen:

If the download speed is not dropped (it is 400 mbits), I can browse the configuration webpages of the archer really fast while downloading big files.
If the speed is dropped to 280 mbits, viewing the configuration webpages of the archer is really slow.

Seems if the speed is dropped, the archer cpu is running under full load and if the speed is not dropped, the load on the archer cpu is not so high.