Is it better with RDRAM or SDRAM? Should I get it was 256 or 512MB? Is there motherboards for SDRAM and RDRAM that supports over 512MB? Is it better to have WinXP home or professional edition? Is it reasonable to get just 1.5Ghz or 2ghz?If I get 64Mb for video card, what kind should it be? Should I wait until the middle of next year to get a new computer?