The PEX4S553B 4-Port PCI Express Serial Card (with breakout cable) lets you add 4 RS232 serial ports using a single PCIe expansion slot, with an included 1-to-4 cable enabling you to add 4 serial ports to a single low profile slot.
The serial card features a native single-chip design that provides optimum reliability and speed, reducing the CPU load by up to 48% over conventional bridge-chip serial cards - a cost-effective solution for connecting legacy serial devices to PCIe-enabled computers.
The multi-port serial adapter includes both full profile and low profile/half-height brackets for compatibility with standard and small form factor computers, and is compatible with a broad range of operating systems, including Windows®, Linux, and MAC OS.
This product is a replacement for our PEX4S552B card.
Backed by a StarTech.com lifetime warranty and free lifetime technical support.

• Native single chip design
• Includes a full profile and low profile/half-height bracket
• On chip 256-byte depth FIFO in transmit/receive path of each port
• Single-Lane (x1) PCI-Express with throughput up to 2.5Gbps
• Supports hardware and software flow control
• Supports data transfer rates up to 250Kbps on each port