Hi, PC fans are operated with 12V, so you definitely need a 12V power supply. However, this fan is PWM (pulse width modulation) controlled, which means that PIN4 of the connector must be supplied with 5V to provide 100% fan power. If you want less power, the signal must be modulated accordingly.
The simplest solution for this fan would be an external PWM fan controller (e.g. Noctua NA-FC1), or you can use a fan without PWM, which can then usually be influenced by voltage regulation (12V=100%).
The SilentWings 3 is also available without PWM, 5V from a USB power supply would bring a correspondingly lower performance, but it would work.

You can find more on the subject on wikipedia (https://en.wikipedia.org/wiki...).