I can see clearly now...
I recently went to the optometrist to get my prescription updated, and if you have glasses or contacts, I'm sure you've gone through the little dance: "Okay... which is better, the first one? or... the second one?" as he or she flips through various lens strengths until you find your sweet spot.
The new version of Flight Simulator is going through the same sort of thing, as far as our terrain system goes. Since this is an area near and dear to my heart, I'm happy get a new prescription, so to speak.
In the coverage of Flight Simulator X seen in the February 2006 PC Gamer magazine they mention a 16X increase in terrain detail. Where does that number come from? And what does it mean?
Well, in previous versions of Flight Simulator (like the current version Flight Simulator 2004) we used 256 pixel X 256 pixel sized squares that cover roughly 1 kilometer square area of space. That represents a resolution of roughly 5 meters per pixel.
From altitude that's not so bad.
It looks a bit like this from a hundred meters or so:

5 meters per pixel (256 X 256 textures)
If we move it up a notch and use a 512 pixel X 512 pixel image to represent the same 1 KM of space we see a lot more resolution:

2 meters per pixel (512 X 512 textures)
By going all the way up to a 1024 X 1024 image we get 16 X the resolution (16 256 X 256 images fit into one 1024 X 1024 image):

1 meter per pixel (1024 X 1024 textures)
So which would you choose, number 1, number 2, or number 3?
Not sure?
Why not take a look at all three in this link (~500k file) :
EYE CHART