Hello,

First of all I want to apologize for my english. It is not my native language and I know it is not perfect ;)

My problem is that I can not reach maximum download speed of my internet connection while using TP-Link Archer C3150. 

I did not saw this problem before because I had 300Mbit Internet and it was working with full speed. But week ago I changed speed of my Internet from 300Mbit to 500 Mbit and I noticed this problem.

I have Compal Connect Box modem/router from my IPS working in Bridge Mode. It is connected with my Archer C3150 (WAN port) and my PC is connected to C3150. I have 500 Mbit from UPC Polska (it is my ISP) but I am able to reach only 350/360 Mbit (on LAN and WiFi).

But when I connect my PC directly to modem from my ISP everything works fine and I can reach 500Mbit. Situation is even more interesting because when my PC is turned off and I am testing speed on my smartphone it also can go up to 500Mbit, but when PC is working WiFi is also limited to 350/360 Mbit. I laso checked if my LAN speed could be better when I turn off WiFi but it did not help.

So it looks problem is in my Archer C3150 settings or router itself. I checked all cables connectimg my PC directly to the modem with them to be sure but they are OK. I have restarted Archer C3150 to its default but it did not help, firmware is the newest one. I am using integrated network card (Intel I218-V) and driver is also up to date. I restarted internet setting in Window 10 but without result. I don't know where exactly is the problem. Below I attached screenshots with speed testing and with my settings.

Speed test - PC conected directly to IPS modem

Speed test - PC connected to C3150 (modem -> router C3150 -> PC)

I hope You can help me with this problem.

Best regards