The B3 was announced yesterday and it is the latest stepping of the P55 core-logic chipset. The P55 are motherboard chipsets that have full support for the new Core i7 and i5 processors based on the 45nm Lynnfield core. Among the features of these processors are the support for eight PCI Express 2.0 x1 ports (2.5GT/s), one PCI Express 2.0 x16 (which can work in x8 mode for dual graphics boards setups), six Serial ATA-300 ports with RAID levels 0/1/5/10, up to 14 USB 2.0 ports, Intel high-definition audio and Ethernet.

The P55s were developed by Intel as platforms not only for the Core i7 and i5 CPUs, but also for the central processing units that were in, or will enter, development. One such CPU is the Clarkdale processor, which uses the 32nm fabrication process, the DDR3 memory controller and 45nm transistors for the integrated GPU.

“Current P55 boards as well as new P55 boards should support Clarkdale. As always end users should check with their board vendor before upgrading,” George Alfs, an Intel spokesperson, said.

The B3 is more of a revision of the B2 than anything else. It uses the same architecture, has the same pin arrangements and identical electrical, mechanical and thermal specs. The only noticeable upgrade is the integrated support for more future processors.

The specific modifications to the B3 chipset are a new MM number and S-spec numbers, and a processor MRC/microcode update (which will provide the aforementioned expanded CPU support). As such, motherboard makers will not need to modify the design of the boards, but will be required to use new storage drivers and update the Bios and the storage driver from Intel MSM 8.9 to Intel RST 9.5.

The first samples of the P-55 B3 stepping have been available since October 2, but the first commercial shipment will be on the 7th of December. Combinations of the B2 and B3 will become available by February 5th, 2010.