My 4770K CPU was stably overclocked to 4.6 GHz before I moved on to the current 3-monitor setup with dual GTX 780 in SLI connection. Since the system crashed a few times due to overheated CPU problem while running P3D (that’s right, P3D, not FSX), I have no choice but to lower the clock speed to 4.2 GHz.
Obviously, even though P3D is said to have shifted many processing works to the GPU, it is still a CPU-intensive program. With lowered clock speed, my system’s CPU temperature lingers around 55°C, and adds another 5 to 10 degrees in general while flying over high density areas. No more crash has encountered since.

