At the same speeds the move from the Intel® Core™ 2 Quad to the 1st generation Intel Core™ processors would show about a 15% to 20% performance improvement. Next the move from 1st to the 2nd generation Intel Core processors would yield around 10% to 15% performance improvement. The move from the 2nd generation Intel Core processors to the 3rd generation Intel Core processor is yielding around 6% performance increase. So at the same speed you would most likely well over 30% performance increase in overall performance. While games don't draw as much of their performance from the CPU you would still see some good performance increases by moving to the Intel Core i5-3570K and that is before you ever have a chance to overclock the processor.