You would never be able to predict this, which is an unfortunate thing about powerline IMO. You just have to buy the modems and see how they perform on your particular wiring.
It's a strange pattern and I'd be interested to solve the mystery. Not many powerline debugging tools available though, not to say none
And yeah it's just a bit of a weird black box, and also fundamentally it's exploiting a nontrivial system to do something that had little relationships to its design goals. I don't know anything about electrical systems but I assume there is all kinds of random shit that can disrupt Powerline links while still being fully within the design envelope of the power system.
A very expensive "up to 1000mbps" kit maxed out at ~200 when both devices were plugged into the same outlet. It just got worse with distance.
It's highly variable in my experience. I've had it work pretty well in some situations and barely at all in others.
I have certainly never got 1000mbps. I think I have got 300 at best. In my office I can only get about 50 even though it works pretty well in other parts of the same small apartment.
... Which is kinda annoying coz they aren't really all that cheap for something you have to just buy and then find out later if it actually works!
Rock solid and reliable networking =)
People tend to want speed, speed, speed, but tons of use cases are totally fine with a reliable 100 Mbps. For a lot of remote monitoring stuff, even 1 kbps is enough if it works reliably. Not everything needs to serve up a webpage.
> MoCA (stands for Multimedia over Coax Alliance) is a technology that uses the existing coaxial cables