A i5 4690k will almost be comparable to a i7 4790k.

i7 offers more hyper-threads (if i recall). It's mostly used for more intensive games (such as Crysis 3), or if you're into editting, Adobe Premier/After Effects/Photoshop.

To be honest, that's normal. I guess.
This is Mor Dhona at 12:40am on a Sunday Morning:

Not that many people are there, which would explain the high FPS in MD.

Now, if you take into factor the abundance of people, that would drop to maybe 30-40fps.
You can't compare frame rates in MD, because that zone is stupid packed.

These are my specs if you're wondering:
i7 4790k 4.0 GHz
16GB 1866 MHz Ram (Forgot brand, sorry.)
GTX 970 4GB FTW.

-shrug-