_JP_
07-07-2006, 20:56
Yay ! 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.
As we also mentioned earlier, Greyhound will be the first desktop processor to support HyperTransport 3.0. Part of the specification for HT-3 is backwards compatibility with older revisions of HyperTransport, and the forward compatibility of the AM2 socket confirms that. However, it’s important to mention that even though AM3 CPUs will work in the AM2 socket, HT-3 allows for 5.2 Giga-transfers per second, while current AM2 motherboards top out at 2.0 Giga-transfers per second. Even though the additional headroom is likely not completely necessary, quad-core CPUs will certainly benefit from the additional bandwidth to the DDR3 memory.
There is no word yet on the number of pins the new socket will require, but since AM2 sockets are forward compatible with AM3 CPUs, we can at least deduct that AM3 will have fewer than 940 pins. Furthermore, since Socket AM2 is forwards compatible with AM3 CPUs, it is also safe to say that AM3 is not a land-grid array (LGA) socket. AMD will switch its Opteron platform to an LGA-1207 socket on August 1, 2006. AMD has not announced when Socket AM3 will be released, although since it would be the first HT-3 "ready" socket design, it seems likely that K8L and AM3 for the desktop will launch simultaneously.
Source: Guru3D (http://www.guru3d.com/newsitem.php?id=4119)
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.
As we also mentioned earlier, Greyhound will be the first desktop processor to support HyperTransport 3.0. Part of the specification for HT-3 is backwards compatibility with older revisions of HyperTransport, and the forward compatibility of the AM2 socket confirms that. However, it’s important to mention that even though AM3 CPUs will work in the AM2 socket, HT-3 allows for 5.2 Giga-transfers per second, while current AM2 motherboards top out at 2.0 Giga-transfers per second. Even though the additional headroom is likely not completely necessary, quad-core CPUs will certainly benefit from the additional bandwidth to the DDR3 memory.
There is no word yet on the number of pins the new socket will require, but since AM2 sockets are forward compatible with AM3 CPUs, we can at least deduct that AM3 will have fewer than 940 pins. Furthermore, since Socket AM2 is forwards compatible with AM3 CPUs, it is also safe to say that AM3 is not a land-grid array (LGA) socket. AMD will switch its Opteron platform to an LGA-1207 socket on August 1, 2006. AMD has not announced when Socket AM3 will be released, although since it would be the first HT-3 "ready" socket design, it seems likely that K8L and AM3 for the desktop will launch simultaneously.
Source: Guru3D (http://www.guru3d.com/newsitem.php?id=4119)