VR-Zone got two ABIT NF7-S Rev 2.0’s in their hands; This boards were made with NVIDIA’s latest chipset revision, A1 (stepping C1). They reviewed the board earlier, now they decided to look at the difference between the older and the newer core:
The C1 steppings overclock higher at lower voltages than their predecessors but they hit the same ceiling eventually. The A3 cores take a higher chipset voltage to hit this ceiling. Therefore, for those who are into modding their boards, the Rev. 2.0 boards offer little benefit in overclocking over the Rev. 1.2.
You can read the review here.