GT-AX6000 - Slower speed than my ISP router

[vanhorts]

I got the GT-AX6000 as I wanted a nice router with VPN capabilities. Managed to set it up fine with the VPN and everything, but the speed that I get is very underwhelming.

I have a 1 GB connection.
With the ISP's router on 5Ghz I get ~500mbs, where with the GT-AX6000 I get ~200mbs.
Connecting via cable gets me ~900mbs.
I believe that this router should get the same speed or better??

I'm using WRT Merlin 3004.388.4.
I have tried a lot of different configurations that I found online but none did the trick so far.
Tried disabling QoS, disabling MU-MIMO and beamforming.

Really at a loss here with no idea what do. Any advice?
I can give more info if needed.

Thanks

 

[ColinTaylor]

Check the TX/RX speed of your client under System Log - Wireless Log.

 

[vanhorts]

I have this:

Also the channel is 52/160.

This also varies considerably.

 

[ColinTaylor]

That looks OK.

Are you testing this with the VPN turned off?

 

[vanhorts]

With the VPN on and off I get the same speeds.

 

[ColinTaylor]

Strange. You could go to the router's Network Map page, select Status in the System Status window and monitor the CPU usage when doing a speed test. Are you hitting a CPU limit maybe?

 

[vanhorts]

Doesn't seem like it, here is a screen from it while the test was running:

 

[ColinTaylor]

Certain functions on the router (like OpenVPN) are single threaded. One of your cores is running at 100% so that's probably creating a bottleneck.

To identify the specific process you'd have to SSH into the router and run top.

 

[MDM]

Try 100/160 or some other channel at 80 wide...
Seems to me like congestion, and the other WiFi must be off!

And also what Colin said.

 

[vanhorts]

I think Colin got the problem correct. With the VPN off the speed goes to about ~550mbs and the cores are barely used.
I don't know why I remembered getting bad speed with the VPN off.

I don't think there's any way to get around this to achieve a faster speed with the VPN?

Looks like this is the best I'll have then.

 

[ColinTaylor]

Using WireGuard instead of OpenVPN sometimes has a lower CPU load for a given throughput.

 

[MDM]

With consumer ruters, yes.

Try WireGuard VPN, might be a bit faster...

P.S.
Colin was faster..