Difference in performance from i3 2120 to i5 3570K?

[admin89]

There is big difference between Haswell and Ivy Bridge (30%) . i3 4130 @ 3.4GHz is equivalent to i5 3570k @ 4.4GHz , just saying...
Ivy Bridge is slightly faster than Sandy Bridge (5~10%)
If you have Z77 mobo atm , getting i5 3570k and overclock it will bring you more improvement .
However , if you're using H61 mobo atm , you should sell it and upgrade to Z87 mobo + i5 4670k