AMD revealed the Bulldozer-based Zambezi desktop processor will require a new Socket AM3+ motherboard. The company initially planned to stick with AM3, but further along the design process they realized that the current socket couldn't support all of Bulldozer's new features. Fortunately, it will still be possible to use older processors in AM3+ motherboards.
"When we initially set out on the path to Bulldozer we were hoping for AM3 compatibility, but further along the process we realized that we had a choice to make based on some of the features that we wanted to bring with Bulldozer. We could either provide AM3 support and lose some of the capabilities of the new Bulldozer architecture or, we could choose the AM3+ socket which would allow the Bulldozer-base Zambezi to have greater performance and capability," the official said.
The compatibility with older microprocessors allows AMD to simplify transition to the new micro-architecture and process design since the new AM3+ platform will support inexpensive chips from day one. However, such compatibility also means that AMD Zambezi processors will only support dual-channel memory controller. Considering the fact that all modern high-end Intel Core i7 processors with up to six cores feature triple-channel memory controller, it is unclear how AMD plans to "feed" eight cores of Zambezi with dul-channel DDR3 without creating bottlenecks.