I think the issue is that you have some sort of adaptive QOS doing downstream rate limits on the LAN ports of the Asus box. Check your settings.

Thanks for all this.

Spoke to a network engineer. We tested the Asus speed (using its own speedcheck) via AX client on 5Ghz and i'm getting 900 up and down so nothing wrong with the connection. Conclusion is simply that the usb c to ethernet adapter simply cannot process speeds that fast regardless of it being a 1GB port.

In reply to a post by jimmybond007:

Conclusion is simply that the usb c to ethernet adapter simply cannot process speeds that fast regardless of it being a 1GB port.

Hmmm a USB-C based Ethernet adaptor should be able to fill a 1Gb/s connection - and it appears that yours can, at least on upload, but not download which is quite odd.

Can you try with another laptop/PC connected to the LAN port of the Asus. I still suspect you could have an issue on the Asus router rather than the machine that you are connecting to it.

I have done that with an Apple Mac and it's the same. The engineer is basically saying that the processor of the old mac and the adapter cannot pass the speed though. When we do a speed test on the router under Adaptive QoS/Internet Speed I get 900 up an down therefore that just mean the router is working fine.

I also get about 700 on AX clients.

What’s the vintage of the Mac? Is it a desktop or MacBook(Pro)?

macbook pro mid 2010. (core 2 duo). Have just ordered a Nighthawk AX8 to sort this out once and for all!

If that resolves the Asus can be returned.

In reply to a post by jimmybond007:

macbook pro mid 2010. (core 2 duo). Have just ordered a Nighthawk AX8 to sort this out once and for all!

If that resolves the Asus can be returned.

Gotcha. Yeah I've got one of those still kicking about on the shelf somewhere!

The USB ports on it aren't USB-C though, so may go towards explaining the results you're seeing.

Apple's implementation of USB-C came around 2015/2016 (and is typically coupled with Thunderbolt3), so good for 40Gb/s - I run my 2017 MacBookPro with a wired 10Gb/s connection via its power/data connection back to an OWC Thunderbolt3 dock.

Edit - Don't know why I didn't notice this before but my 2010 MBP has a built-in RJ45 Gigabit ethernet port, exactly like this...

https://scottbw.files.wordpress.com/2011/03/ports.png

Does your not have an RJ45 port built-in?

Edited by Pheasant (Thu 13-May-21 18:52:43)

Possibly confusing you,

Tried 2 (and now 3) devices
2010 Macbook pro with built in ethernet
Surface Pro with usb-c to ethernet

and now PS4. PS4 gives me 500 up and 100 down so better. So everything points to the poor processors of he devices and not the Asus - IMHO

In reply to a post by jimmybond007:

So everything points to the poor processors of he devices and not the Asus - IMHO

doesn't your Surface Pro have a Core i5, much newer than a core2duo in that Mac ? If you have third party security software that can interfere with the ethernet.

it does, but it then has to go through a cheap chinese USB C to ethernet adapter.