StarTech.com 4 Port PCI Express USB 3.0 Card - PEXUSB3S42V

Each pair of ports shares a dedicated 5 Gbps channel. So, while the card has four ports, the maximum theoretical speed is limited by these two independent 5 Gbps channels.

Connecting the optional SATA or LP4 power is highly recommended, especially for power-hungry devices like external hard drive enclosures or charging multiple devices, to ensure stable operation and deliver up to 900mA per port.

The card physically fits in a PCIe x1 slot, but it will operate at the limited speed of a single lane (5 Gbps total, not 10 Gbps), and performance may be significantly reduced. It is designed for and performs best in an x4 or larger slot.

UASP (USB Attached SCSI Protocol) is best supported on Windows 8 and later operating systems, as well as newer versions of Linux. Older operating systems will still function but will use the traditional Bulk-Only Transport (BOT) protocol.

This card specifically supports the USB Battery Charging Specification 1.2 (Apple Mode only) for faster charging of compatible Apple devices. For Android devices, charging speeds will depend on the device's own charging capabilities and the standard USB 3.0 power output (up to 900mA if power is connected).

Yes, the card typically comes with a driver CD, and drivers are also available for download from the StarTech.com support website.

Ensure the card is fully seated in the PCIe slot. Verify that the correct PCIe slot (x4 or larger) is being used. Check if the optional SATA/LP4 power connector is securely attached if required by your system's power needs.

Confirm that the card's power connector is attached if using high-power devices. Try connecting the device to a different port on the card. Ensure you are using the latest drivers for the card. Check the USB cable for damage.

Verify that both the card and the connected USB device support USB 3.0 (5 Gbps). Ensure you are using a UASP-compatible enclosure and OS for maximum speed benefits. Check that the optional power connector is attached. Avoid using the card in a PCIe x1 slot, which will limit speed.

Ensure your operating system supports UASP (Windows 8 and later recommended). Confirm that the connected USB device or enclosure also supports UASP. Check if the correct drivers are installed for the PEXUSB3S42V card.