Is VIDEO CARD MEMORY imPORTANT?

Hello,
I have a 1Ghz processor, 1GB ram & directx 9.0c compatible video card, but the video cards memory is only 8MB .... i wanna play gta 3 and my system meets all the requirements except the video card has only 8MB memory....as opposed to the 16MB(Minimum) memory required by gta3. can i play it on my pc without changing the current graphics card i have(ATI Rage XL) flawlessly or is it not possible?? PS: if not gta,i need to know whether games that require normal memory of 16MB in a VIDEO CARD are playable on an 8MB card....... is card memory really THAT important?? someone confident of their expertise answer me please :) it would b kind of u :)