Asus XT8 Slow backhaul using 5GHZ-2

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New Around Here
Hey folks, I posted the issue (I think it is an issue, but happy to be corrected) to Asus Support, but given their bad track record of service, I post my problem here to see if I can get additional help. :)

I have a twin pack of XT8. The wireless backhaul between the main router and the node is quite slow, and it is no way near the advertised speed.

I have done the following setup for my testing:
1. I attached a USB 3 drive to the node (NOT the main router).
2. move the 2 units next to each other (20 centimeters away).
3. I have a surface laptop 3 (supports WIFI 6) next to the routers too (1 meter away from the 2 units)

If I connect my laptop using a wired cable (via the 1GB port or 2.5GB WAN port) to the node and doing file transfers via SAMBA from/to the disk, the speed is around 65MB/s for both read/write, this is my baseline speed for my test to compare against.

Now the testing:

Scenario 1: I connect the laptop to the main router using Ethernet cable, and the router connects to the node via wireless backhaul using 5GHZ-2, and the 2 units are 20cm away. I can achieve around 50MB/s read from the disk to my laptop. however, I can only get 10MB/s when writing to the disk from the Laptop.
Scenario 2: I connect the laptop to the main router using an Ethernet cable, and the router connects to the node via WIRED backhaul. In this scenario, I CAN achieve both read/write at speed of 65MB/s

So clearly, when connecting the 2 units using wireless backhaul, it can not achieve the baseline speed, especially when writing files to the disk drive. I have tried to perform a hard reset on both units and reconnect them but it didn't help. I also tried to tweak a few settings for the 5GHZ-2 band, there is no improvement either (not an expert here so not sure i have tweaked the right thing).

I understand the wireless backhaul is not using 160MHZ but only using 80MHZ as far as I can tell from the wireless log (maybe due to the restriction of radio spectrum here in Australia), but still this writing speed is way too slow and not acceptable. I wonder why reading speed is a lot faster, there must be some kind of QOS going on here but I have no QOS enabled at all.

I wondering how to improve the read/write speed to make it close to the baseline speed? it is not possible to run cables in my house.


Part of the Furniture
Yes, everyone has. Not a recommended way to use a router. :)

Not your router, but this is (still) the latest thoughts on USB attached router storage.

Basically, in your case, the translation from file system to USB connection to Wi-Fi transmission is just too much overhead to expect anything more than you're seeing.

This isn't a problem that has a solution except to stop using your router like that and use a file server via a proper NAS. Ignoring, of course, all the marketing claims otherwise.


New Around Here
Thanks for replying, but I think you are missing the point. My complaint here is the 5GHZ-2 is not performing as it should, copying files from a disk attached to the usb port is just my way of testing to show how slow the 5GHZ-2 is.

I don't intend to use the router as a NAS, but just want to see why 5GHZ-2 is a bottleneck, and the speed is too far off from what it should be.


Part of the Furniture
Okay, maybe I did miss your point. :)

But then, you're testing wrong. :)

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