Games lag even tho my computer has higher specs

[deadaspect]

So my computer doesnt have insanely high specs but it has better specs than it needs to run games that I lag on such as League, CS:GO and like every game I play.
I've had this issue for so long and can't find the problem.

OS: Windows 10 64bit
CPU: i7-4790 CPU 3.60GHz
GPU: NVIDIA GeForce GTX 970
Motherboard: LENOVO ES14039283 31900058 STD

My friends who have worse specs than I do don't lag on games that I lag on. Sometimes They have like 140fps and I only get like 30fps. I've tried lowering the games settings, updating drivers and I've even tried factory reseting my computer. None worked and I don't know what to do.

PLEASE HELP!
Thanks.

 

[superninja12]

is the hdmi/displayport cable plugged into the motherboard?