I made another topic to further explain this phenomena, you should go read it after reading this one.
It's graphics card upgrading season and the one thing on a lot of people's minds is "will my system bottleneck this graphics card?" And the answer to that is... it depends. Not just on your hardware, but the game itself.
What is a bottleneck?
I'll leave it up to this video to explain it.
But if you are the type who wants me to get to the point: