Intel Hub Architecture (IHA) also known as Accelerated Hub Architecture (AHA) is a replacement to the North Bridge/South bridge architecture.  It is Intel´s architecture for the 8xx family of chipset, starting with the Intel 810. It uses a Memory Controller Hub (MCH) that is connected to an I/O Controller Hub (ICH) via a bus. The bus that links the Memory controller hub to the I/O controller hub is known as the Direct Media Interface (DMI). The speed of this bus is 266 Mb/s.

Intel Hub Architecture

The processor is connected to the MCH and the MCH is connected to the ICH. The MCH manages all the memory related components like the RAM and the AGP. ICH on the other hand, manages the input output bus  like the USB, PCI Bus etc…

Thanks to the high speed channel and high bandwidth interfaces the Intel hub architecture is much faster than the earlier North bridge/South bridge design.