ive known guys to build comps with all high end parts. then try to run some modern high end games at high settings and not be able to.
they try new ram, more ram, new power supply, more cooling, new drivers, new drivers, new drivers, new video card.
and in the end they had perfect hardware all along, just the damn screen was to big for the game.
try your tower out on a friends larger monitor before you get your own. see the huge difference in performance.
the video lag is very noticeable.
my framerates jump from 66 to 121 on crysis from just switching from 24wide to 19wide.
and i have frikin quad frame per gpu rendering