My computer's promising specs are not preforming as I'd like

Donutaco37

Commendable
Feb 1, 2017
3
0
1,510
I am not a huge computer person, so try to tolerate my lack of knowledge. I have recently built (kind of) a gaming PC, and with the help of friends who have some more knowledge with this stuff, chose some pretty good parts. As I've gotten my games I have noticed that people I know who have computers with the same specs as me, or even a bit worse, can run most things considerably better than I can. I don't know really what I am asking for here, but something along the lines of "why can't I run things that I should be able to run?" Here are my specs:

CPU: Intel Core i7-6700 CPU @ 3.40ghz
GPU: GeForce GTX 960
Motherboard: Intel Z170

Thanks,
Cade