Originally Posted by dellbert
An LCD has 1-2million transistors, so we're talking much less than 1W. (Compare that to 300-400million transistors for the CPU or GPU).
The backlight typically uses from 0 to around 5W depending on brightness.
There is no direct correlation between LCD size and backlight power unless you're comparing panels that have exactly the same brightness, same light dispersion, same materials, etc. I read that something like 98% of the light from the backlight is lost, so manufacturers can tweak much more than the power consumption to improve brightness.
In any case, this is all theoretical. When somebody buys a 6400, they can do a battery run-down test, and we can compare it to a 9400 with similar specs.
But anyway, yes, it is all academic. It will be interesting to see which does better on battery life, but I'm going to say that it'll be the 15 inchers since most people on here are getitng the 7800 on their 17s.
everyone would agree that a x1400 uses a heck of a lot less juice than a 7800.... (but then of course, it's not the "changing only the screen" that this whole thread is about... )