Saphire 6850 in p6644y

It looks like it will fit, your case is 7 inches wide, and 16.9 inches in depth. and the card is 9.37 inches long and 3.86 inches wide. You should probably measure out if it will fit just in case, and remember that this card is two slots wide so make sure you have space for it. Then make sure you have a good enough psu, 500W should do. Make sure you don't cheap out on your psu either, Corsair is a great choice