Slow speed from AX210 to Asus RT88U Pro

[rodja123]

This is my first post. Hello!
I have been pretty puzzled by the speed I am able to get from from Intel AX210 devices connected to an Asus RT-A88U Pro on the Wi-Fi 6 on 5Ghz band

To make the story short. I have a small server with 2.5Ghz wired connection to the Asus Router. The server is running iperf3 server
I put a laptop with AX210 right next to the router, verify on windows that the signal is optimal and the negotiated speed is 2400Mbps
Run iperf3 client and get ~550Mbps. If I use the parallel option I can go up to ~1.5Mbps
I put my pixel 6a right next to the router, verify on Android that the signal is optimal and the negotiated speed is 2400Mbps
Run iperf3 client and get ~1.35Gbps. If I use the parallel option I can go up to ~1.75Gbps

Why? What I am missing in the AX210? I tried other devices with AX200 and AX211 and it's the same ~550Mbps.

Thank you all.

EDIT: Retested and updated the numbers.

 

[OzarkEdge]

What I am missing in the AX210?

Updated OEM driver?

OE

 

[rodja123]

Hello!

I updated the driver and the results did not change. However, I did narrow down the problem to... Windows!

I booted my laptop with a Linux live image and I can get 1.3Gbps single thread and 1.7Gbps multithread.

Now the question is: why is the Windows single thread perf so low?

 

[RMerlin]

Try a different test. Microsoft recently published a post indicating that iperf was a bad way to test throughput with WIndows, in part because the current build of iperf is old and not optimized in any way for Win32. Try doing a large file copy over SMB for instance. My own AX210/AX211 had no issue giving me in the 1.5-2.0 Gb/s throughput when copying files, with the laptop running Windows 11.

 

[sfx2000]

Some insight here...

Testing ntttcp as an iperf3 alternative in Windows 11 (and Linux) - CNX Software

ntttcp (Windows NT Test TCP) is a network benchmarking utility similar to iperf3 that works in both Windows and Linux written and recommended by Microsoft

www.cnx-software.com

ntttcp is a suitable substitute for iperf2/3 on Win systems...

A bit curious though how iperf3 would work on WSL with Ubuntu, as that network path thru the NT kernel is a bit different than NT (Windows) userland...

 

[sfx2000]

I put a laptop with AX210 right next to the router, verify on windows that the signal is optimal and the negotiated speed is 2400Mbps
Run iperf3 client and get ~550Mbps. If I use the parallel option I can go up to ~1.5Mbps

FWIW - you're actually not that slow - the 2400Mbps is the PHY rate, not the upper layer IP whether it is TCP or UDP...

iperf2/3 - yes, you need to push parallel streams to get a decent feel for throughput, as a single stream itself might not push enough data to kick a wireless interface into full speed...

 

[tgl]

FWIW - you're actually not that slow - the 2400Mbps is the PHY rate, not the upper layer IP whether it is TCP or UDP...

Yeah ... rule of thumb is you can get about two-thirds of the PHY rate in sustained real-world throughput, so 1.5 to 1.7Gbps is just about what to expect. The rest of it goes to packet overhead and listen-before-talk rules.

 

[RMerlin]

Hm, I wonder if Microsoft or Intel broke something. I used to be able to get well over 150 MB/s a few months ago. Now, I can download over 150 MB/s, but upload are only around 60-70 MB/s, despite having Throughput Booster enabled.

 

[rodja123]

FWIW - you're actually not that slow - the 2400Mbps is the PHY rate, not the upper layer IP whether it is TCP or UDP...

I am aware of this and I am not complaining about the multi-threaded iperf3 performance. I was just surprised of the difference between my phone's (and linux's) single threaded and windows' single threaded performance.

Anyway, you did point me to the right direction. I was using an outdated version of iperf3 (3.1.3). I grabbed the latest one (3.17.1) and voila' problem solved

Thank you all!