In plain non Chinese terms.... You will benefit much more from a video card then from a cpu upgrade, as long as your cpu is a dual core and above 2.6ghz per core it won't slow down your gfx, if you have a dual core cpu under 2.6ghz then you may benefit from a cpu upgrade. If your cpu is over 2.6ghz and you have an average video card, you will see a big performance increase from changing your video card.
Ie. change from 7900gt to a 8800Gt 512mb will give you a very noticable performance increase.
Myself, i have a 8800GTS 320MB, i will see only a small benefit if i upgrade to a 8800 Ultra or a small-moderate if i get a 9900GX2, i personally will be waiting until the next generation of Nvidia gfx and then will upgrade again. there is not much point going from a 8000 to 9000 because they are pretty much the same chips with different clock speeds.