Add four rs232 serial ports to any pc using a single pci express expansion slot the pex4s952 4 port native pci express rs232 serial adapter card with 16950 uart allows you to turn a pci express slot into 4 rs 232 db9 serial connections the four port serial card is based on a native single chip design that harnesses the full capability of pci express pcie providing optimum reliability and speed and reducing the load applied to the cpu by as much as 48 over conventional serial cards