I have an i5-4670k clocked at 3.4 GHz, a GTX 1070 GPU, and until today been running with 8GB RAM. The sim would take a few mins to get up to full FPS when I started a flight, switching views or swinging the cameras for the first few times in the cockpit would cause it to stutter. Opening the screen top or the main menus also took a short time to respond. I just added 16GB of RAM, the total is now 24 GB, and it has made a big difference. The sim reaches full FPS almost immediately on starting to fly (I get 30+ FPS most of the time and can hit 50 occasionally with nearly all settings on at least High), changing camera views is smooth straight away, and now all menus are instant.
Edit: I also used to get big stutters on landing but just now on my first flight the landing was very smooth, and firing up Notepad++ to record the airfield was very fast indeed. I’m soooooo pleased. Volanta too opens very quickly now.