line rate or more commonly referred to as powerline linkrate is not associated with tcp throughput i.e.internet throughput. i can get 1200mbps link rate on PA9020P but only 120-130mbps internet rate measured on ookla. at router direct i get 490mbps on ookla speedtest.

@manim 

 

In plainest terms you are correct, however as is true with wireless and ethernet factors such as distance, and obsticles will reduce the speeds you get.  This is why 5GHz is faster at 10 feet than it is at 30 feet.  Same is true for powerline.  Each "Hop" is a barrier that must be transversed and each barrier reduces the over all not work speed, as does the overall distance a signal travels over the powerlines.

@Carl 

I do not believe this analysis is correct.  Behind the circuit breakers are two solid copper bus bars, each connected to the separate "phases" of a typical residential electrical supply.  Here's a link to a typical box showing how phase 1 and phase 2 are connected to "every other" breaker position.

In your picture, the breakers on the left are "double breakers", where two breakers take up the same phyical space as one single breaker.  So the top two on the left are connected to the same phase.  The next two to the other phase.  The next two to the first phase, etc.  On the right, there is a 240 volt breaker, which has one regular size breaker connected to one phase and a similar breaker connected to the other phase.

 

So, adapter #1 is on one phase and adapter #2 is on the other phase.  The signal path is not down the bus bar at all.  It goes through the main breaker from one phase to the other and then back down the bus bar to the other circuit breaker.

 

And, the communication signal goes through the bus bar, not through each of the individual circuit breakers.

 

The quickest solution is to put both breakers on the same phase, either by swapping the two double breakers on the bottom right, or by swapping the powerline circuit on the bottom double breaker with one of the circuits on the breaker above it.

 

I cannot make out whether all those breakers on the bottom right are the same amperage (they would have to be for this to work).  Also, isn't it a bit strange to have a Powerline adapter on the 15 amp circuit?  "Where I come from", 15 amp circuits are for lighting and 20 amp circuits are for wall plugs.

 

p.s. I am wrong a lot, and people usually are quick to point out my mistakes.

@UnWired 

 

Yeah we actually just swiped the image of a electical panel from google images to use for the example to illustrate the point that each jump will reduce the over all transfer rates. 

@Carl

My disagreement is with the concept of "jump".  The bus bar is a solid bar of copper running from top to bottom with lugs sticking up at every other position.  A signal going from the top of the bus to the bottom of the bus does not "stop" along the way.  It arrives simultaneously (speed of electricity) at every breaker on the bus at the same time.  It goes down all of the circuits at the same time.  On all but one of them, the signal just fades off to the end.  On the circuit with another adapter,that adapter senses and decodes the signal and may place a return signal back on the wire, which also goes everywhere.

 

There is no intelligence in the copper bar or the circuit breakers.  The signal does not go down one circuit, come back up and then go down another circuit.

 

Maybe I should have paid more attention in physics class.

 

I wonder, however, if the total size of the electrical wiring has any effect on performance.  In coax networks, for example, "splitters" dramatically reduce electrical signals, by 3dB per split (50%).

@UnWired 

 

You probably know more than we do.  This is more of an electical situation than a networking one, and networking is what we know.  I tried to explain it as best I could in lamens terms from the information given to me by our engineering team.  Essentially what was told to me is that a powerline signal traverse linearly through each cirucit breaker between the base adapter and the remote one.  This is where i use "Hop" to explain this transversal communication.   Each breaker or hop the signal is degraded. much like a wireless signal when it hits a barrier.  Load on a circuit or unflitered appliances like a washer and dryer or microwave can also create electrical noise that will reduce the signal.  Finally the quality of the lines is also a factor.  poor or old power lines, powerline with eroded or damaged insulation will also affect performance.  

 

 

I hope that helps clarify the post a bit more.  

@Carl 

 

Sorry, I tend to be "too literal", and the science behind Powerline remains much of a mystery.  I completely agree that distance, quality of wiring & connections, etc. will degrade a signal until it is finally unusable.  It would be really useful to have some direction on how to mitigate issues.  Obviously, I can't rip out my 60 year old electrical wiring. But aren't there device(s) can be used to reduce that "electrical noise"?  Are there things that can be plugged into the outlet, and the microwave/dryer/washer/refrigerator plugged into them?  How much does going from one "phase" to another phase reduce throughput?

@UnWired 

 

The easiest thing to use to filter the noise out is a surge protector.  As for how much does the phase to phase reduction affect the adapater's speed, I can't answer that right now but I can inquire.  I would guess that the answer is going to be Depends on........ But we can ask.

@Carl 

 

Thanks for the tip.  I have been "over thinking" this, haven't I.  As long as the surge protector claims "noise reduction", that means it has more then just the surge suppressor thyristors.  Back to the web I go!

@UnWired 

 

I don't think you are overthinkg, infact you've given me more knowledge on the subject then i had before.  You are just simiply trying to get a complete understanding of how these devices function which is always a good thing.  To my knowledge all surge protectors will filter the electrical noise, through simple power strips will not.  If you find any infromation to counter that please let me know.