Up-to this very moment ity was believed that AMD was going to release the Thuban six-core processor in May. AMD might introduce its chip quite a bit earlier though, April 26th.
AMD will likely launch three versions of the Phenom II X6, namely the 1035T, 1055T, and 1075T. All these CPUs will be built on the 45nm manufacturing process and will be compatible with AM2+ and AM3 sockets. This could imply that they will be compatible with not just the 890GX-based motherboards, but also existing AM2+ and AM3 boards (provided a BIOS update is made).
Among the features that the upcoming chip is expected to boast is a dynamic performance boost technology similar to Intel's Turbo Boost. Known, for now, as C-state performance boost, this technology will dynamically disable unused cores and overclock the operational ones, when running applications that rely on clock speed and cannot take advantage of multiple cores.
AMD will be showcasing the six-core at CeBIT 2010, where its 890GX chipset (which launches tomorrow) will also be demonstrated as part of a range of new motherboards.