Potentially faulty motherboard causing internet issues

[CallumP227]

Hello, i have fibre internet with 80Mb down and 20Mb Up and i get that speed on all devices except on my PC that is connected via cable. i have updated the network drivers and it still doesnt get anywhere near that speed. (67Mb down and 2.5Mb Up). i have had and engineer out and the only thing he could think of was something called a dry solder on the motherboards ethernet port, however i have the same issues on the desktops Wi-Fi. again i get the full speed on other devices such as my laptop.
Can anyone help me resolve this issues please? Specs are as follows:
http://uk.pcpartpicker.com/p/DYkyqs

 

[reedo_43]

Ping your gateway with a -t and see if you drop any packets. example from command prompt: ping 192.168.0.1 -t or whatever your gateway is.