It's definately noticeable on a large monitor, i can tell the difference between the vga and dvi on my 20". The dvi port on the monitor quit working and i had to use the dvi>vga adapter on the video card so i could use the vga input on the monitor, and there is a definate difference. As far as video cards with both vga and dvi out im not sure how that works. Every card i have ever had has either been single vga out or dual dvi out.