Tried it all, no change:

 

@lostdoc 

 

What speed do you get if you bypass the router and connect a PC direct to the modem or internet connection?

@ArcherC8 

this is direct with modem

 

Oddly direct to the modem is the same speed, might not be a router thing - maybe motherboard? or some update? since before I was getting 400mbps so I know its possible

@lostdoc 

 

Try different Ethernet cables first.

 

Then check the settings in your PC. May need to update your drivers.

 

Try a different PC if you can.

 

It can also be your ISP, your modem, or the IPS cables.

 

Let us know what you find.

@lostdoc 

 

If I'm reading this thread right, you have 1GB ISP service, and at one point in time you could get 400Mbps on the PC, and then it dropped to 100Mbps?

 

However at first you posted this:

 

lostdoc wrote

Updated to the most recent firmware and my speeds up/down-dropped to 100mbps - tested my modem and gets 1gig up/down easy.

Updated the Ethernet lines to cat6, no change

Updated security and other settings in AX6000, no change

 

Was never able to get to the 1gig up/down, but was able to get to 400ish for a while, now (after the lastest update its very slow) - plus this is wired in directly

 

What did change from the first post to the last?

 

I do have some questions though?

 

• What is the make and model of the 'PC'?
• What OS is it running?
• What is the network adapter.

 

I ask because normally 1Gbps would provide over 800Mbps speed, and you appear to never have gotten that?

 

Getting even 400Mbps before would have one think it was QoS getting in the way.

 

So more questions:

 

• Did you have different ISP speed service before?
• Did you have a different router before?
• Do you have this same speed problem on all devices, I mean are all devices reporting the same speed.

 

If you are connected with a USB device that connects an Ethernet cable the USB connection could cause that slow 400Mbps speed.

 

If on Windows (don't know how to do this on Mac's or other devices) you can see the Connection Speed of the cable. It is using the Control Panel and double click on the adapter you are using and you can see it:

 

 

It should be 1Gbps if the cable/port is good. Showing 100Mbps, well it could be a bad socket on the router or PC or a device setting under the properties in Device Manager.

 

Last thing though, you are changing connections on the modem. Some modems 'remember' what was last connected to them. Change the connection and you might not get full speed. Normally one would have all devices connected to the modem power off. Then power on the modem, wait for it to fully come up, and then the next device, the router or PC and turn that on, and when up, do the test. PC's connected to router should also be off, although if left on shouldn't matter, but best to have them off until everything is up.

 

What I'd do I guess is first power off the modem and disconnect the router from it. PC off as well. Power up the modem, and when up, connect the PC and power that up and then test.

 

Not sure where you are testing from either? I assume https://fast.com/, Most ISP's have their own Speed tests. Results can be unreliable off their network.

 

Speed tests can be Unreliable as well. I just tested at FAST.COM (I have 400Mbps service which is generally overprovisioned up to 20%), and I got this:

 

Note, it was jumping somewhat during the test too. It DOES have the Upload speed correct as my service is actually 400/20 Mbps.

 

Testing in my ISP's test portal:

 

 

One note about the differences, IPv6 on top, IPv4 on the bottom. My ISP, Spectrum, uses dual stacked DNS's, so I go out to my ISP and it will determine if Iuse one or the other. They do not have an IPv6 DNS for me to us.

 

OK, let me test another way? I have an Archer A20 which has its OWN Speed test and here is the History of the test results and the day I took them, including today:

 

So what is my Internet speed and 'who' do you believe?

 

Still confused? I am too, so I opened my iPhone 12 connected via Wireless and get this result:

 

 

Hmm, sort of matches what the A20 router sees?

 

Why my PC is geting slightly less? Could be other things going on (I don't see anything?) or even some h/w problem, which I am having and replacing the 8 year old PC. I know at one point I was gotting 470Mbps down on this PC. Could even be a cable issue?

 

I for one wouldn't trust FAST.COM.

 

@lostdoc,

 

By the way, it can be the PC, and maybe even the router/ISP.

 

This morning on reboot of the PC, I again ran my ISP Speedtest:

 

 

Getting on the PC what I expected. Even @ SPEEDTEST.NET:

 

 

Not so on FAST.COM:

 

 

Note that I am now using IPv4 the prior test shows, but not FAST.COM. I did mess with the router settings though yesterday. Made some changes with the type of IPv6 methods used, and tested with no changes. At least I thought I put it back to what it was?

 

I am now using for the Internet Dynamic IP (SLAAC/DHCPv6) and the LAN is just DHCPv6.

 

If you have IPv6 enabled, try speed testing with it off.

 

Right now, I'm in agreement with the wireless speed of the iPhone (expect for the FAST.COM test which is bogus).

@lostdoc,

 

I'd like to add FAST.COM, for me at least is beyond doubt WORTHLESS:

 

 

As you can see, it is speed I know I can't reach on both DOWN and UP. Shows IPv6 testing too (which is OK). Also it was bumping up and down during the test vs. the others above being almost flat.

 

So use SPEEDTEST.NET would be my recommendation or that of your ISP's speedtest if they have one.

 

I guess I also show that sometimes within the PC, speedtests can change. Maybe some connection issues you were not aware of?