Power draw, temperature and noise
As I told you, overclocking Vishera CPUs increases a lot the power consumption. For FX-6350, we have 83% power draw increase, which transforms directly to heat. As for noise, maybe 1500RPM doesn’t sound much, but when you use 2 120mm fans in a push-pull config, it can get quite annoying. This is why I repeated the measurements using the Silent profile for fans in the motherboard’s BIOS.
As you can see, the temperature under load at standard frequencies is higher, but the fans work at much lower RPM, which makes the noise barely noticeable. For overclocking, the motherboard feels that the CPU needs more cooling, so it runs the fans at full RPM.