@Acastello 

I think your speed is limited by incorrect cables towards or from your power line.

You need CAT 5E or higher.

My guess is you are using a CAT 5 and because of that your speed is limited to 100Mbit max.

A friend of mine had the same issue between his X60 and a switch. Because of the CAT5 between his main deco and switch he had two deco units with a limited speed of 100 Mbit and one (his main) with 300 mbit

Hello @JJ10 . Thank you for your answer.

I'm using CAT 6 to connect telecom provider's router and P6. I get a speed around 400Mb on living room from the first Deco P9, that is connected to a router. The problem are on second and third unit. Maybe is something related to power line, as you said.

I read that Deco P9 not only use power line to delivery you internet connection but use together wifi between units, as a bandwidth redundancy (power line + wifi). 

Does anybody here knows something about that? 

@Acastello 

Hi, you could have a check of the signal source on the two satellite P9s and confirm it is on the PLC and wireless backhaul.

By the way, have you checked the Ethernet speed from one of the satellite Decos?

If possible, could you please try to swap the location of the 3 P9s so that we could check whether the issue is related to the location or the specific Deco unit:

How to Setup the Satellite Deco to be the Main Deco?

@TP-Link 

This is a print screen of the first satellite Deco, in the middle of the house. I thought that Deco worked throught powerline but i'm noticing that it combines wifi signal with powerline. My internet provider cable arrives at the living room (main Deco).

Is it possible to change the second Deco (in the hallway) to be de main Deco? Will this make it work at a better speed? 

@Acastello 

Hi, the main Deco needs to be connected to the ISP router by cable all the time.

So did you want to use the first satellite Deco as the main Deco?

Have you tested the Ethernet speed directly from the second and third Deco units?

Thank you very much.

@starmanj 

the main Deco needs to be connected to the ISP router by cable all the time.

Yes, it is.

So did you want to use the first satellite Deco as the main Deco?

No. I asked because I thought that this could improve my network speed.

Have you tested the Ethernet speed directly from the second and third Deco units?

Yes. I have 500Mb with my provider.  Here are the speeds on Deco:

- Main deco connect to ISP router:  around 450Mb (if have only 5Ghz network turned on). If I turn on 2Ghz, I have 90Mb of speed /80Mb upload.

- first satellite (main hall): 90Mb download / 80Mb upload

- second satellite (bedroom): 90Mb/ 80Mb upload

I tested using my ISP speed meter site and Okla. Results have small variations. 

Thanks,

Andre