Review on ARCTIC F9 PWM PST CO - 92mm Continuous Operation Cooler with PST-Port: Grey Case Fan with Synced RPM Regulation (AFACO-090PC-GBA01) by Pavan Cormier

Long time trying to upgrade old noisy fans in HP Pavilion. I ordered two of these devices. Although the units were very quiet, they just couldn't get enough air and the system kept shutting down. So I removed the new fans, applied a new coat of Arctic MX-4 cooler thermal compound, and installed both stock turbo fans. It seems that the noise issue isn't fan related at all, it's caused by the old thermal paste that was originally applied to the CPU at the factory basically drying out and losing its conductivity. With a new coat of fresh thermal paste, the old fans not only kept the system cool, but they now run much slower and are just as quiet as the new fans I was planning to use to replace them.