I have an older Dell XPS 630i desktop that is running (2) Nvidia 9800 GT graphics cards. I was running 3 monitors @ 1920 x 1080 just fine, but now that the 2460 x 1440 monitors are coming down in cost, I want to upgrade all 3 monitors to higher res., The cards have 4 DVI outputs combined, so hook-up isn't my concern. Will the cards, both being 512 DDR ram, be able to playback vids at an acceptable rate? If not, what is the least cost way to upgrade to cards that can handle the task, remembering this is a 2008 MB?