I'm a bit late but there really is no difference except for when your computer isn't doing much the 3770S runs at a lower clock peed, 3100MHz, vs the 3700 which runs at 3400MHz. the MAX power usage for the S is 65W vs 77W. i would get the 3770K because you can overclock it but beware if you are going to do so it does get very hot and you will absolutely need a aftermarket cooler. but between the 3700 and the 3770S, get the S. both have the same integrated graphics, they both have the same max frequency, just one uses less power and that usually means less heat and they are the same price on newegg.ca/com. get the S.