My screen resolution always blurry. Why?

Why is it when I run something in fullscreen mode on a lower resolution, the screen doesn't stretch out?

• So I run Borderlands or Fallout 3 or blur or whatever in fullscreen mode, expecting a fullscreen. Well I get one, provided the game resolution is set to 1366x768. If I lower it to try and get a better framerate, still in fullscreen mode, the actual game screen shrinks and is srrounded by a black border. I thought of running my games in a lower resolution after lowering my main resolution, but when I lower that, it just does that same thing my background. I want to play fullscreen because I like the big screen, but I want to play with good framerates. Older games used to stretch to fit the screen no matter how low the resolution, the pixels were just stretched more. Anyone know how to do this with newer games. I'm tired of playing Borderlands so little, especially because I play in fullscreen mode not window mode for a reason >_>

• Answer:

  Its unlikely to be the game at fault. Its more likely your graphics card settings. For example, in ATIs CCC, you can specifically state what you want your card to do with lower resolutions... stretch to fit the entire screen, stretch but keep the same aspect ratio, or 'centred timings', which means the picture will appear in the middle of the screen surrounded by a black border. I do not know if nVidia's control panel has equivalent settings because I have not used one of their cards for some time.