content: If the price difference is low then always go newer.    edit:  Now at a PC so I have a little more time to look.  The 7700 is higher clock speed (2.8) and fewer cores (4).  The 8750 is lower clock speed (2.2) and more cores (6).  BUT, the 8750 has higher Turbo speeds (4.2/3.9) than the 7700 (3.8/3.4) and more cache (9 vs 6 MB).  The 8750 will be better in most applications to the tune of 30-50%.