Can all PWM fan's speed be controlled by the motherboard?

[King Mustard]

Or is there some specific term that I should be looking out for in the product descriptions that tells me if they're controllable?

 

[King Mustard]

All fans I know of that say they are PWM use PWM signal on pin-4 to signal the fans PWM control circuit and pulse the 12v power to the fan motor.

Hope that makes sense.

Fantastic, thank you