To further expand on this, "southbridge" is what we now call a chipset expander (or 50 other company or product line specific names).
Its a switch that has a bunch of unified PHYs that can do many different tasks (non-primary PCI-E lanes, SATA ports, USB ports, etc), leveraging shared hardware to reduce silicon footprint while increasing utility, and connects to PCI-E lanes on the CPU.
alt Hacker News
To further expand on this, "southbridge" is what we now call a chipset expander (or 50 other company or product line specific names).
Its a switch that has a bunch of unified PHYs that can do many different tasks (non-primary PCI-E lanes, SATA ports, USB ports, etc), leveraging shared hardware to reduce silicon footprint while increasing utility, and connects to PCI-E lanes on the CPU.