ROD WiFi slow?

Using Internet 7.07 and WLanB 7.07 on a 3B+.

With my !ESP32Cam application, transferring a UXGA image that’s 301K takes a mite under a second using wired ethernet, as the ESP32’s built-in server isn’t particularly fast or capable.

When using WiFi, it takes nearly thirteen seconds. Dropping in some trace information, it looks like it is alternating between 1.4K and 4.3K blocks, but there’s an evident pause in between each block.

It’s the same code in both cases, and it uses the URL fetcher in both cases.

Are there a lot of overheads that make WiFi go screwy with small block sizes? This is clearly a pathological case as nothing else that I use here has triggered such a response. WiFi might be slightly slower than wired, but there’s a convenience and ShareFS and general internet use are fast enough.

And if I bump up the quality and the image is ~700K? I can go put the kettle on and come back and, well, it’s still going. ;)

Both ROD’s and ROOL’s WiFi are extremely slow, in my experience.

WiFi might be slightly slower than wired,

Contended connection vs. uncontended.
With Wi-Fi your transfer rates will vary depending on the number of other devices in the same subnet contending for access to the router airspace. At best the transfer will approach the declared rate, one way, if there is no contention for the airspace from other devices.

A typical wired switch/router will transfer data to you and back the other way, simultaneously, at a rate that is only dependent on the port speed, while also handling similar requirements from another port, provided the switch/router backplane speed exceeds the total of both.

Then, factor in the RO system contention for processor time and limited buffering.
I suspect that if the system was using a spare core and a chunk of reserved memory for a buffer, the transfers might show a noticable improvement.

With Wi-Fi your transfer rates will vary depending on the number of other devices

The thing is, it is just this one device that is treacle slow when using WiFi on RISC OS. It’s fast enough using a mobile phone. It’s fast enough using wired ethernet (note that the ESP32 is always using WiFi itself, no choice).

I can get decent speeds using WiFi to a mobile phone (also WiFi) using FTP to transfer files. ShareFS also works okay using WiFi on all devices.

It’s just this one device that seems to send data in alternate 1.4K and 4.3K blocks with a notable pause between each block.

Last two sentences