The i5 runs rings around the X4 840. It is indeed the better CPU. You, know your 2 options tell me, you have 100-200$ of budget for the CPU? If you plan to do overclocking, get the Phenom II X4-955 BE. If you do not intend to OC. get the Intel i3 2100. Both will cost you around 135$. Really, right now, they give the best performance to $ ratio. GL!