WiFi Module 5A - Performance

[Richard Schaefer]

I have a headless N2+ with a WiFi Module 5A that I use for development ... i.e. I ssh into it to build software.
When I use the LAN interface to access the system ... everything is very responsive.
When I use the WIFI interface to access the system ... there is often 1 to 2 second pauses to get any response from a simple command such as ls ...
I do not have anything running in the background ...

Are there any special configurations issues I need to be aware of with the WiFi Module 5A ?

[odroid]

When we tested the Module 5A, we could see very steady 200~250Mbps throughput with 5Ghz band.
https://wiki.odroid.com/accessory/conne ... oid_series

If your AP supports only 2.4Ghz band, use an OTG-to-Host cable with your WiFi module to avoid USB 3.0 RF interference.
https://www.intel.com/content/www/us/en ... paper.html

[Richard Schaefer]

I tried with both the 2.4 and 5.0 Ghz band.
Similar behavior.
Throughput is not the issue .... latency is. It's like it sometimes takes 1 - 2 seconds to get started. Then it's OK.
This is not a Router/AP issue ... I have lots of computers that I access via SSH over Wifi using this Router/AP (Cisco router).
I also changed to a different WIFI dongle and the problem disappeared:

Code: Select all

[    2.349023] usb 1-1.2: new high-speed USB device number 3 using xhci-hcd
[    2.494108] usb 1-1.2: New USB device found, idVendor=148f, idProduct=3070
[    2.495856] usb 1-1.2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[    2.497572] usb 1-1.2: Product: 802.11 n WLAN
[    2.499248] usb 1-1.2: Manufacturer: Ralink
[    2.500914] usb 1-1.2: SerialNumber: 1.0

So there is definitely an issue with the Wifi Module 5A driver when transitioning from idle state ... or handling small packets (i.e. keystrokes) at user typing speed.

[mad_ady]

Note that there's a way to disable sleep for wifi - see if it helps: https://askubuntu.com/questions/695867/ ... management. See the powersave reply.

[Richard Schaefer]

Thanks for the powersave ptr ... that seems to resolve the issue I have been seeing.