screen saver which turn display off even if system will be intensively using

[JanuszChmiel]

May be, that you will think on Me, that I AM crazy. That I Am asking you for this feature. But because I do not see at all, lightning display is really redundand for Me. And I could save some battery power and especially, LCD display and neon light generator would not be so overused. Samsung Android phone SM-G550T1 have integrated special feature build in The settings. When user press power button fast for twice, screen is totally dark. Not dimmed, really dark. so I AM dreaming, if screen saver can also be made so display could stay dark even if system will be used. Or it is impossible because of video BIOS or kernel drivers?
The problem is how to make this feature also on modern EFI systems.