I see people are mostly getting the i5 2500k. What's the difference between 2500k and 3570k? One is second gen and other third? Which one is better?
Ivy is just an architecture shrink of Sandy, it doesn't bring anything new to the table in terms of performance really, besides PCIe 3.0. For as long as it's more expensive than the 2500k there isn't much reason to pay more for it.