Do GPU's only render whats on the screen or all the surrounding in the game

gpuboy

Reputable
Apr 13, 2014
17
0
4,510
For example if i am playing GTA VC on a low end notebook and i am looking at the sky or on the terrain the frame rate seems to improve significantly. Do GPU only render on screen images.

I need to know if GPU's can render specific amount of effects and texture res ON SCREEN
I also need to know if specific Polygonal count is counted only ON SCREEN