Nvidia MCP89E chipset for Centrino 2 without DDR2 support
Nvidia's MCP89E chipset for Intel's Centrino 2 differs from the MCP79 chipset in certain aspects of the specifications.
In contrast to the MCP79 the new MCP89E chipset will not support DDR2 RAM but only DDR3 RAM which needs a little less energy. MCP79 and MCP89E are pin compatible and thus can be used without fundamental changes of the board layout.
While the MCP79 supports 2 GiByte modules, the MCP89E can also deal with 4 GiByte modules. There is a difference regarding the PCI Express lanes, too: The MCP89E offers only eight of them while the MCP79 offers 20 lanes. But therefore the MCP89E is supposed to be able to run with a lower voltage and thus have a lower power consumption says VR-Zone.