Just tested and yep screen goes off only, fans stay running.
You can turn fans off by manually adjusting them through the screen, packaged software or Phoebetria.
I only have three fans connected although it can take 2 or 3 standard speed fans per channel if you are willing to sacrifice a small percentage of top end speed.
The only gripes I have with the unit are that sometimes the fans speed up and down by 100 RPM or so for no apparent reason, something which I hear that Phoebetria apparently fixes. Also I wish the backlight colour was changeable. I even tried to mod the LEDs but they are so firmly rooted in the light pipe that I was scared to remove them.