AMD launched Bulldozer about a month ago, but the initial CPUs were only for desktops. As a follow up, AMD has today released the server variants of Bulldozer. There are a total of 18 CPUs launching today, and they are branded as Opteron 4200 and 6200 series, although some of you may be more familiar with the codenames "Valencia" and "Interlagos". AMD actually began the shipments of 4200 and 6200 series in September but the lineup was not officially released until today. Below is a specification table. 

We did an overview of Bulldozer lineup in our Details on AMD Bulldozer: Opterons to Feature Configurable TDP article. The basics are still the same. 4200 series is compatible with 4100 series' C32 socket; and 6200 series is compatible with 6100 series' G34 socket. That means existing motherboards are compatible with the new CPUs, although a BIOS update may be needed. The main difference between 4200 and 6200 series, on top of the core count, is the CPU configuration support: 4200 is limited to dual CPU configuration whereas 6200 series supports up to four CPUs in one system. 6200 also has a quad-channel memory controller, whereas 4200 is limited to two channels. 

While Bulldozer was a letdown for desktops, it may be more attractive for servers. The biggest shortage of Bulldozer was its poor single-threaded performance, but server software is usually well threaded and can hence take advantage of all Bulldozer's cores. 

Johan has received Opteron 6276 CPU and is already working on a review, so stay tuned!