I am looking to buy a laptop and having trouble as to which processor to choose.  Which processor is better? an

Intel® Core™ 2 Duo P8700 (3MB cache/2.53GHz/1066Mhz FSB)  

or 

Intel ® Core ™ i7 720QM 1.6GHz (2.8 GHz Turbo Mode, 6MB Cache)

I know that the i7 is the newer processor but i am being thrown off by the number of GHz.  

If anybody can help I would greatly appreciate it