AMD has released details of its next-generation desktop CPU interface, Socket AM3, to its OEM partners. In a mildly surprising move, AMD has revealed that AM2 will accept AM2 or AM3 CPU packages. Additionally, recent roadmaps have confirmed that AM3, AMD's upcoming desktop CPU socket, will not be backwards compatible with AM2-package CPUs. Roadmaps and memos have also confirmed that this AM3 package will be for AMD's "K8L" architecture, and not for the upcoming 65nm AM2 Brisbane CPUs scheduled for launch this December.
The most recent AMD roadmap is also very clear to state AM3 "supports either DDR2 SDRAM or DDR3 SDRAM, but not on the same motherboard." This is great news for upgraders, as there is a very clear upgrade path: CPU, motherboard, and then memory. This also infers that AM3 CPUs will have both DDR2 and DDR3 support on the integrated memory controller. DDR3, like DDR2, has 240-pin, but the two formats are not pin-compatible.