Mach I fans speed?

[JetJam]

is it true that only the front fan goes from high to low speed at startup and the rear fan is always on low?
also meaning only the front fan is controlled (high-low)?

[Raiden Zero]

hm, atleast at my unit both fans run at full speed when i start my unit.
after it reaches -50°C (on display) both fans are @low speed.