I have a pretty bad computer, but I used to be able to run games like combat arms and magicka with no problem. That was back on a 1024x768 reso. Now I have a 1920x1080 monitor, and my pc cant run anything on it, and only some games will run okay if i switch the reso down, the rest just stay running horribly. not to mention, on the right side of my screen, there is a black box of unused monitor, as if my resolution wasnt set high enough, but its on the highest it can go. can anyone help me?
if you have a computer that barely met the specs for the aformentioned games then of course you will notice bad (or non) performance when you increase the performance load by using a larger monitor.
you might want to list your specs on here so we could advise you better. the problem might lie in an inadequate video card (or the whole thing might need upgrading) we need to know what to have in order to advise.
your monitor should be ran at its native resolution only (1920x1080), any adjustments to resolution should be done from within the game. some older games are mono-resolution with no options to adjust. these are some of the old 4:3 ratio games from 1995-2000. in such cases (if there is no auto-scaling) you will get black bars on both sides of the screen as it attempts to make your monitor 4:3. i suppose it could push this black bar to one side (instead of both) with some monitors (though i havent seen it)