So i have been using smcFanControl app for a while now. The stock speed is 2,000 rpm and i run mine at 3,000 rpm when on battery and 3,500 rpm when plugged in. I just ordered thermal paste & i am going to re-do it on my Mac since its running hot and and i have never replace it yet. so to stay on topic, there is stuff all over the forums. Speeding up your fans is bad, or its good, it they will die in a few years, etc. Is there any solid proof that its really bad for them?
To my real question... does speeding up your fans truly speed the computer up or does it just keep it cooler. I remember back in my "building desktop days", the colder the comp is the faster it runs. Does the fan speed and the mac running colder have any true effect on making it faster??
The short answer is that running your internal fans at a higher baseline speed has the potential to increase performance, as does providing supplemental cooling directly onto the CPU/GPU.
Now for the long answer.
Laptops have cooling systems with a built-in cooling capacity that is typically less than desktop cooling systems. One reason is that laptop have more tightly packed internal components so there is less space for airflow and a greater likelihood that heat from the CPU/GPU will bleed off into other components as well as the entire computer/enclosure. The built-in cooling system typically use one or more small fans connected to a heat pipe that is connected to a heat sink that is connected to the CPU/GPU. This system is designed to primarily cool the CPU/GPU as they are the primary heat generators.
By increasing the baseline speed of your internal fans or by providing supplemental cooling directly onto the CPU/GPU you will remove more heat from the CPU/GPU, which reduces the amount of heat that bleeds off into other components and the overall computer/enclosure. Combining both a higher baseline internal fan speed and supplemental cooling will further reduce temperatures and increase cooling capacity. However, if you are concerned about reducing the lifespan of your internal fans then adding supplemental cooling is a good solution.
With less heat in the system then your computer will have additional passive heat sink cooling capacity available when a heavy/intensive workload is applied and the initial heat spike that occurs before the fan spin up to full speed will also be reduced. Once the fans spin up to full speed then it is only a matter of time before the heat being generated by the CPU/GPU builds up in the system at which point the heat may overwhelm the laptop’s built-in cooling system resulting in performance reduction as the computer throttles processor speed in order to avoid overheating. Since internal fans are already spinning at maximum speed then supplemental cooling directly onto the CPU/GPU will be required to reduce/eliminate throttling and regain performance.
Throttling can happen frequently and the performance reduction can be severe, while the frequency and amount of throttling depends on a variety of factors, such as the laptop model, its built in cooling capacity, the laptop’s CPU/GPU power, the intensity of the applied workload, the duration of the workload, the ambient temperature, and other factors.
