I went shopping for graphics card and am very confused on how to buy the best card. With which card can I play all PC games available in the market at 1050-1080p resolution? I found a card Sapphire Radeon HD5570 2GB DDR3 memory. Also I found Sapphire Radeon HD 5670 1GB DDR3 memory. Actually most games have 1GB memory of the ones i saw. How important is memory? Is HD5570 card better than HD 5670 because it has more memory? Do games really need more than 1GB of memory?