StarTech.com 4 Port PCI Express RS232 Serial Adapter Card - 16950 UART - 256-byte FIFO Cache - PCI E Serial Card (PEX4S953LP) - This PCI Express RS232 serial adapter card lets you add four RS232 (DB9) serial ports to your computer through a PCI Express (PCIe) slot - The 4-port serial PCIe card provides a max baud rate of 921.6Kbps and 256-byte FIFO cache for high performance: