Can someone explain....????

[ferrarinews]

Hi.
I want a resolution of 1208 X 800 in Gran Turismo 4, but i don't understand were i put, see below :
[Image: 88593730.jpg]
which says "Resolution" and what makes? And which says "D3D internal"?
If i put less in D3D, the image becomes less clear, if i put more, the image becomes more defined. What is for "Resolution"?
Really, i can understand. But one thing i no, the game becomes more fast, or less fast.
Someone explain, because in the Guide, i can understand.
Thank all.

[refraction]

D3D internal = the resolution it is rendered at
Resolution = the resolution gsdx uses when you go full screen