That isn't how it works. The content all starts out the same, and the by default the video card will output the exact same image, but the problem is that every monitor is different. So what you see on your screen is not the same as what I will see on my screen, even if we are both looking at the exact same image. Even two monitors that are the exact same model number can vary enough to look different.
I understand that, but what I'm saying is when you are doing that, you are using your judgement and taste to determine what looks "right" to you. What looks right to you may not look right to me. Doing calibration this way is in no way actual calibration or anything close to it.
but it is how it works, let's say your monitor appears faded, so you increase the contrast, now you have crushed blacks & whites in the process, every middle value looks better, but you have lost information at the extremes, this has nothing to do with judgement, the goal is to see every available value if possible, it's an extremely basic casual way to see if something is wrong (& i have seen it, some monitors cannot show all blacks no matter what settings, some show those junk 'game' or 'movie' modes alter the image a ton, etc)
i never said i was calibrating two screens to match each other or match an official reference, it's only to attempt to display what is being sent to the monitor (or driver) without missing anything
the 'only' situation that software tweaking can solve is for example if the monitor is doing something incorrect to the signal that results in it mismatching the scale of those values: my FP241VW did this when using hdmi, i cannot use the same as dvi settings or rgb-full on it, it permanently crushes blacks at all times as if it assumes all hdmi input is supposed to be limited... so i had to only output software/consoles as rgb-limited, then readjust the brightness/contrast of the monitor so that black shows up as to black instead of grey & white returns to white instead of grey because i know the monitor can display those values & the rgb-limited ones did not reach them
If he has AGP the best Card he could get is a HD4670 lol.
i feel like there was a single fermi, kepler, or maxwell agp from someone