Small PCIE to 19PIN USB3.0 Expansion Card Function: PCIe based expansion card that provides a 19pin USB3.0 header connection for internal USB 3.0 use. Performance: The fast expansion card can reach around 140 MB/s on PCIE1.0, but can only reach over 300 Mbps on PCIE2.0. Power: Supports a small 15pin PCIE power connection or a 4pin floppy drive power supply. Compatibility and usage: Note that it can only be used with PCIe standard hardware and must be plugged in to work when in use. Size and design: Compact, small form factor suitable for tight builds. Use scenarios In a compact PC or HTPC, add USB 3.0 internal header connectivity for frontpanel USB ports or internal USB devices. In small form factor systems that require USB 3.0 support, especially when a PCIe slot is available and a dedicated power source is accessible. In setups where a motherboard relies on PCIe expansion to provide USB 3.0 functionality, enabling additional internal USB connections without occupying additional motherboard headers.