I am confused when it comes to directX support and video cards. I am running an old Geforce4 mx440. I see that it only has DX7 support. What happens if I try to play a directx 8.1 game? I was going to get a Radeon 8500 for $15.00 but I see that it only supports DX8.1 and I may want to play a game that runs under DX9 so I guess that $15 radeon 8500 is also useless. Is it best to buy a brand new card with every release of direct X?