amd am3 ddr3

Reference plans for motherboards based on AMD's desktop AM3 processors are already starting to mature. Socket AM3 is the successor to AMD's Socket AM2+, and is not expected to make an official release until 2008.

Current AMD guidance suggests its AM3 processors will be compatible with existing chipsets. AM2 processors, however, will not be compatible with AM3 motherboards. This same guidance claims AM3 processors will work with AM2+ motherboards.

The initial reference boards that support AM3 processors will be based on an AMD RS780 northbridge and an AMD SB700 southbridge. The northbridge and southbridge communicate with each other via a 4X PCIe lane. The northbridge communicates directly with the CPU using a HyperTransport link.

The RS780-based AM3 reference boards will feature 12 USB 2.0 ports along with 6 SATA II ports. For audiophiles the board also features integrated AZALIA HD Audio.

Also making its appearance for the first with AM3 will be DDR3 memory support. Since AMD places its memory controllers directly on its processors, the DDR3 DIMM slots will communicate directly with the processor using a 128-bit bus. According to current AMD reference posted at ChileHardware, there will be a total of four DIMM slots.  

AMD has not publically announced DDR3 support for its Phenom or Barcelona family processors.  Previous roadmaps indicate that DDR3 support will likely come with its 45nm shrink next year, but the company has also confirmed DDR3 will be present on the Bulldozer CPU architecture.

The RS780 AM3 chipset will also come with integrated graphics. The AM3 reference boards will feature a VGA and HDMI connection, along with a TV-out composite cable that features S-Video along with HD TV-Out.  This is only a reference design, so there is no guarantee these features will pan out in production products.

--------------------------------------------------------------------------------