AC88U Merlin, speed drops when powerline master device connected

[m3tpe]

Background:
--> Comcast Gigabit Internet, tested to send 940mbps when modem connected directly to the computer

Setup:
Comcast Modem (Bridged) -(cat8)- Asus ac88u (wifi off)

Connected to the AC88U
-- Custom built computer cat8 cable
-- EERO Mesh cat6 cable
-- TP-Link AV2000 Powerline, for IPCams cat5e cable

If I speedtest from modem to ac88u to computer, the speed is 940mbps.
If I plug in the Eero, I can hit around 800mbps
Now if I plug in the TP-Link AV2000 powerline device, it drops to 650-700mbps.
Any idea what is causing this? Could it be the cable problem from the AV2000 device to the router?

 

[WuTang LAN]

The powerline adapters use your internal home wiring to send data. It's very susceptible to cross-talk and interference as electrical home wiring is both untwisted and unshielded.

 

[m3tpe]

The powerline adapters use your internal home wiring to send data. It's very susceptible to cross-talk and interference as electrical home wiring is both untwisted and unshielded.

So does swapping to a better CAT ethernet cable help? or Ill just have to deal with it, with no improvements...

 

[Makaveli]

So does swapping to a better CAT ethernet cable help? or Ill just have to deal with it, with no improvements...

Putting in a better Cat cable is not going to improve your home wiring.

 

[m3tpe]

Putting in a better Cat cable is not going to improve your home wiring.

My computer is connected directly to the AC88u. So i'm trying to figure out why the speedtest slows down when the AV2000 is connected to the router. I'm not running speedtest through the powerline. I figured the data through the powerline will be compromised, but not when its connected directly to the router.

 

[Grisu]

a better cable cant make any difference if the old one matches the needed rates, and CAT5e does, even CAT5 for some less than 100m.

You wont be faster with a car able to go 300km/h if you are limited to 100km/h, every car able to go 100 will be as fast as a F1-race car.
Of course only if it is in good working condition, for your cable this means not streched or bent with good connectors and well crimped.