(2.0Ghz Sandy Bridge) and Pentium P6200 (2.13 GHz Arrandale) are essentially the same in CPU power with the B940 having a better GPU. Both run 2 cores / 2 threads.
(2.53 GHz) is a small upgrade in CPU performance over B940/P6200. It runs 2 cores using 4 threads with a faster base clock. The Sandy Bridge Core i3-2310M
(2.1Ghz) is nearly as powerful a CPU but having a better GPU.