@delijohn Maybe you simply broke one of the cables - 100 Mbit/s works on two wire pairs, while gigabit needs all four intact.

  @PeterM. I thought TP-Link included cheap cables, so I used a pair of cat7 cables, the same ones who just gave me this result on my wired pc. 

  @David-TP hi,

yes, I've installed the utility. I upgraded their firmware also and I noticed that even on the same socket (both adapters), the speed wasn't more than 500mbps. In speedtests, that wasn't translating back to better speeds and I kept having ~125-140mbps. I tried even with better cables (cat7) and nothing changed. 

The much better speeds were with cable directly from my router, correct. 

  @delijohn hi, i have been having the same problems with the exact same products and thats after troubleshooting my whole home network.

i have done some digging and come up with this from tp link website

https://www.tp-link.com/uk/support/faq/2928/

it seems to suggest that they was never intended for the advertised speed and so will never reach that rate of transfer. 

i would be returning mine but i am too late to do so now.

i am only getting 180Mbps transfer using powerline between my pc and home server using iperf and also a data transfer test, however if i use a 1Gb switch between the two i am getting in the region of 850Mbps so this is clearly just a problem with the product and not being capable of the speeds on the box. 

I would be happy to try a fix to resolve this problem but am very doubtful that there will be one, i am already fully up to date on firmware so that doesn't bode well for any improvements.

i think for now its going to have to be a Ethernet cable installed between the two points to fix this issue.

  @David-TP even if that was true (about 30-40% of the actual speed), I tested the most ideal scenario. In my living room, at the same power socket both powerlines. No washing machines or microwaves, since everything else like that it's in the kitchen or in other rooms.. 

I tend to agree more with @ryansyke and his comment. I'm not sure that the advertised speed should be 1Gbps, since I can barely pass 100mbpsm while connecting both devices on the same socket.. even if I connect one on another room, actual speeds are the same and the tool still says link is between 400 and 500mbps, no matter what I do. 1gbps is a theoretical limit, but when the actual speed is 1/10th, it's kind of.. ridiculous. :( I'll send them back, since I still have the possibility to do it. 

  @delijohn A lot of what's being argued here is the usual misunderstanding of what's being advertized.

Now "up to 1000 Mbit/s" refers to the gross channel bandwidth, and there's an "up to" in front of it.

Obviously, just like with any other transport media that does not have a predetermined quality of carrier, you will never get anywhere near to the theoretical maximum in real life. Just look at your WiFi network's advertized max and your devices' actual connection speeds.

And then, also exactly like on any other shared-media channels (think WiFi, there's only one air for everybody in reach), it's either transmit or receive, and there's a lot of maintenance traffic going on just to sustain the connections.

Summing this all up, actual net payload throughput will be about 1/3 of the actual point-to-point channel bandwidth. Is it much less? Then you're facing a high packet error rate. This may be because your devices aggressively aim for a high connection speed, or because you actually do have disturbances (any cheap CCFL or LED lamps around? Ancient refrigerator? Cheap power supplies and chargers?).

In the case discussed here, where we use the simplest possible kit, the reported speeds are disappointing but actually realistic.

The fellows here who keep seeing "100 Mbit" being reported on the PC: This is the line speed from the PLC to the PC, not the PLC line speed itself. You guys have a bad cable or damaged connectors.

Ok @PeterM., according to your experience, how can the "up to" speeds be achieved? I'm talking about the best scenario EVER.

Living room, not other devices than a TV and a pc, which are on ANOTHER power socket. I find one power socket with three outputs (this is how it's done in Switzerland) and I plug in, two out of three sockets the two PA7017s. TP-Link tool, says connection between them is 500mbps. On my computer, maximum speed is 125mbps. Maximum means that I get it once every 10 speed tests and most of the times, I get 80-90mbps.

Can you explain what am I doing wrong? I've mentioned already that I'm using the cat7 cables I have for my 10Gbit connection directly from my router, to avoid ANY mistake with wrong cables. I tried of course with the cables included in the box. So what's the theoretical scenario, that can give UP TO 1Gbps? In an empty place, without any other device plugged in the whole apartment?