While it is difficult to make exact estimates on framerates, an i7 4790K should be able to handle the aircraft avionics with ease. Most of the heavy lifting of the avionics rendering is shifted away to background threads, so even my piddly i5 4460 that I develop on was able to do a locked 60 fps while streaming yesterday. Of course, this was in an area with little scenery. I would say your performance will mostly be dictated by the scenery and your GPU horsepower, rather than being limited by the aircraft's systems code and CPU speed.