A compelling reason to stick to a dark theme on your Nokia N85 or N86

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It's not everyday that you learn something - I've known for a while that a) OLED displays are supposed to be more power efficient than TFT and that b) the brighter the colours, the more power is actually consumed. But I hadn't realised the scale of the problem until now, with hard evidence from a semi-official Nokia source. Read on for links and comments by me. Summary? On a OLED-screened smartphone, a pure white theme uses 14x as much power as a pure black one! 

Here's a diagram from the original Forum Nokia post (you may need to log in to read it):

What a great little piece of research! Some notes (by me):

  • The difference between choosing a black or dark theme on your Nokia N85 or N86 (or even N8, later this year) can be as much as 14 times! Of course, there are other drains on your smartphone battery, but the display is certainly a major factor.
  • Even for traditional TFT displays, where the backlight intensity is the main factor in display power consumption, there are significant power savings from choosing a dark rather than a white theme - up to a factor of two at best/worse case.
  • Under ideal circumstances, with a pure black theme, an OLED display is around five times more power efficient than a traditional TFT one. Under worst case scenario, with a pure white theme, an OLED display is 50% less efficient than TFT.

Definitely food for thought - this little study deserves plenty of publicity!

Steve Litchfield