Question Internet Speed slow when connected to router (ethernet or wireless) ?


Nov 23, 2013
I bought an Asus ROG GT AX-11000 router to replace an older one I had hoping to improve performance. It worked great for a short while, but then I noticed slow speeds. I did a lot of testing and learned that when I connect directly to my modem, speeds are way faster - often more than my specified speed of 200 mbps down. This only affects down speed, but upload speeds are generally ok at around 30 mbps. I sent the router back for repair, and it was returned with the same problem.

While it was out for repair, I bought another Asus router (RT AC-86U) and it does the same thing. I have convinced Asus to replace the AX-11000 with a new one, but I haven't received it yet. I have good ethernet cables, and use the same ones when testing through the modem and when I add the router. I notice that when connected to the router, speed typically starts out ok, but after about 1 second, it dives and tapers off with a high degree of variability (anywhere from 1 to 30 mbps). My motherboard is an Asus ROG x-570 Crosshair VIII and I've updated bios and all drivers. Any help is greatly appreciated.



Make and model modem?

How are they all connected?

For example (line diagram):

ISP ---coax, fiber, DSL ----> modem ---- Ethernet cable --->[WAN port] Router [LAN ports] ---- Ethernet cables ----> Wired devices and ~~~~~ > Wireless devices

Edit my line diagram as necessary. What incoming cable do you have from your ISP?

Show other devices if any: switches, other routers, access points, etc..