Same here!
Had i5-2400 and it was, ehm, struggle. 4 cores, 4 threads. Constantly limited by CPU.
Upgraded to Xeon E3-1270, same socket, same mobo (8 years old), 4 cores, 8 threads, running just fine on high!
Had issue with clouds due to old GTX770 GPU, swapped for new 1660 OC few days ago and still getting limited by GPU. The old CPU´s are just fine! Motherboard old as hell Z68AP
Screenshot from today´s flight
Just FYI - DDR3 RAM´s (16GB) and SSD (random 500GB) over SATA. All works just fine 
(so far)