For what it's worth, I'm amazed at the hardware still being used by a lot of folk here.
Nearly all the complaints come from folk with hardware from many years ago.
Old video cards and ancient procs!
Some of the GPUs used by those complaining of slow/choppy speeds are years old and a little searching on the web will show the FPS of these are way down compared with later models.
Sure older games will render smoother, that's to be expected, these older cards were made for older games.
These days with more and more data and coding being used means, unfortunately, that one must update hardware. SSE Extremes is right up there with the top 3D games and to experience it's beauty and gameplay one must use "proper" GPU cards. And just because a GPU is new does not mean it is sufficient. It must be powerful as well. In Australia you would be expecting to pay around $400 for such a card.
You will be amazed at the difference.