Is the Southbridge Dead?
The main component on the logic board of the new 2019 Mac Pro is the massive PCIe switch that directs the pool of 64 PCIe lanes to the eight PCIe slots. At the same time, the role of the southbridge has all but vanished. None of the functions of the 33 different ports provided by the Intel® C621 southbridge are in use in a default configuration or the Mac Pro. Here Apple is setting a trend. Future PCs are likely to completely abolish the southbridge . The Mac Pro 7,1 logic board by iFixit . The yellow rectangle marks the Intel C621 southbridge. What is a the southebridge? Early PCs were built around a parallel bus. 8-bit computers from the 1970s would have a case with a passive backplane. Identical connectors would sit next each other, with the corresponding pins tied to each other in the backplane to form a bus. One connector would house a processor card while others would hold memory and input/output cards. In early PCs like the IBM PC and the Apple II the processor and part of the r