I am building a computer with the following hardware.
Intel Core i5 3570k
Gigabyte GA-Z77-DS3H LGA 1155 Z77 ATX Intel Motherboard
OCZ Technology ZT Series 750 Watt Modular ATX Power Supply
EVGA - NVIDIA GeForce GTX 550 Ti Video Card
I noticed that when I power on my computer every fan begins to spin except for the CPU fan. After a short delay, the CPU fan begins to shake and finally spins, however it will stop randomly and start up again while the computer is powered on. Now I am near certain that my original power supply, a Cooler Master that was very loud, didn't have this problem, although I am not 100% positive. I have swapped out the OCZ power supply twice with replacement models and the problem persist. Is it a compatibility issue or is this normal? It seems to me as if the CPU fan is not receiving enough power.
If your cooling is set to passive then the fan will turn off when the heatsink is under around i think 40-40c, then it will start turning slowly, if it gets too hot then the fan will start spinning faster, i think...
You can check in advanced power settings (in the control panel under system and security and under power options).