http://www.planet3dnow.de/cgi-bi ... 1&id=1282840508
"The existing G34 and C32 server infrastructure will support the new Bulldozer-based server products. In order for AMD’s desktop offering to fully leverage the capabilities of Bulldozer, an enhanced AM3+ socket will be introduced that supports Bulldozer and is backward-compatible with our existing AM3 CPU offerings."
"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 majority of the computer buying public will not upgrade their processors, but enthusiasts do. When we did the analysis it was clear that the customers who were most likely to upgrade an AM3 motherboard to a Bulldozer would want the features and capability that would only be delivered in the new AM3+ sockets. A classic Catch-22.
Why not do both you ask? Just make a second model that only works in AM3? First, because that would greatly increase the cost and infrastructure of bringing the product to market, which would drive up the cost of the product (for both AMD and its partners). Secondly, adding an additional product would double the time involved in many of the development steps.
So in the end, delivering an AM3 capability would bring you a less featured product that was more expensive and later to market. Instead we chose the path of the AM3+ socket, which is a path that we hope will bring you a better priced product, with greater performance and more features - on time.
When we looked at the market for AM3 upgrades, it was clear that the folks most interested in an AM3-based product were the enthusiasts. This is one set of customers that we know are not willing to settle for second best when it comes to performance, so we definitely needed to ensure that our new architecture would meet their demanding needs, for both high performance and overclockability. We believe they will see that in AM3+."
