An i3 is a dual core with hyperthreading. An i5 is a quad core without hyperthreading, and an i7 is a quad core with it. This is talking about the normal, desktop processors only, not xeons (6-8 cores), extreme edition chips (4-6, hypertheading), or laptop processors..n i5 is a quad core without hyperthreading, and an i7 is a quad core with it. This is talking about the normal, desktop processors only, not xeons (6-8 cores), extreme edition chips (4-6, hypertheading), or laptop processors..