AMD today has officially released the new A75 and the A55 chipsets, with motherboards based on them to have already begin appearing at the market. With the AMD Hudson D3 chipsets, AMD drops the traditional north and south bridge setup in favor of a single controller. This was made possible by the company's decision to move most of the functionality that is available in the north bridge to the Llano APU.

The new chipsets will power motherboards powered by Llano APUs, which are compatible with AMD's FM1 socket. Although many features of a traditonal Northbridge chip have moved to the platforms A75/A55 chipsets and the APUs, motherboards based on the new platform feature a seperate Southbridge chip.

The A75 chispet includes the PCI Express controller, which packs 16 PCI-E Gen 2 lanes, just as it's the case with Intel's Sandy Bridge CPUs.

AMD's Llano APUs also include a four-lane PCI-E Gen 2 controller for running four x1 slots, two x2 slots or an x4 slot.



The integrated graphics core found in the Llano processor die also communicates through two four lane PCI-E interfaces. The first one of these is used for running the digital video outputs available on the motherboard (HDMI, DVI or DisplayPort), while the latter goes into a DAC found on the PCH for running the VGA port.

The UMI link provides 2GB/s worth of bandwidth in each direction for data communication between the Llano APU and the FCH.

Main specifications of the A75 include USB 3.0 X 4, USB 2.0 X 10, USB 1.1 X 2, SATA 6Gbps X 6 (support RAID 0/1/10), mSATA, PCI Express x1 Gen2 X 4, PCI X 3,2.2 and support for HDD with capacities of higher than 2.2TB (requires UEFI BIOS and only x64 OSes.)

The A55 idoes not support USB 3.0 and SATA 6Gbps but they feature more USB 2.0 ports.



Biostas, Asus, ECS, Gigabyte and ASRock have already showcased motherboads based on the A75 chipset.