[luma]

Your experience is typical even in the cleanest of AC power conditions. Powerline is hilariously oversold and regularly provides less than 25% of the advertised throughput.

This blogger has some great examples: https://specklepattern.wordpress.com/2018/03/03/seven-genera...

The "2 gigabit" adapters top out at 470mbit when both sides are plugged into the same duplex receptacle. That number is cut in half when you move to another room, and it gets worse from there.

Every Powerline vendor, without exception, are using funny math when coming up with their advertised throughput numbers. In no situation will they ever be able to provide 50% of their stated throughput, and more typically it's closer to 10%.

[kortex]

They probably go to the Shop Vacuum Power Rating school of specs. Oh you hit 40A of inrush current for 30 ms? 4500W, call it 6 HP.

They probably hit 2 gbps for 30ms on the same duplex with zero interference.

[Nextgrid]

In this case I should consider myself lucky. I'm getting ~300Mbps out of "AV1200" adapters.