Overview

The StarTech.com PEXUSB3S22 is a PCIe 3.0 x4 expansion card that adds two USB 3.2 Gen 2 (10Gbps) USB-A ports to your desktop PC. Powered by the ASMedia ASM3142 controller, it delivers stable high-speed connectivity without external power. Ideal for users who need extra rear USB ports for fast storage, VR headsets, or multiple peripherals.

Key Features

  • Two USB-A ports, each supporting up to 10Gbps transfer speed
  • PCIe 3.0 x4 interface (fits x8/x16 slots physically)
  • ASMedia ASM3142 chipset for reliable performance
  • No external power required; powered entirely by the PCIe slot
  • Backward compatible with USB 3.0, 2.0, and 1.1 devices

Compatibility & Installation

  • Slot compatibility: PCIe x4 / x8 / x16 (operates at x4 lanes)
  • OS support: Windows 10/11, Linux (kernel driver), macOS (limited; check compatibility)
  • Includes low-profile bracket for small form factor cases
  • No additional power cable needed; ensure motherboard can supply enough power for connected devices

Ideal Use Cases

  • Expanding rear USB ports on a desktop PC when built-in ports are insufficient
  • Connecting high-speed external SSDs to achieve up to 1,000MB/s transfer rates
  • Dedicated port for bandwidth-intensive peripherals like VR headsets or capture devices

Considerations

  • This card does not support USB 3.2 Gen 2×2 (20Gbps); consider a USB4 or Thunderbolt solution if you need 20Gbps
  • macOS support varies; some versions may require additional driver installation
  • When using multiple USB 3.2 Gen 2 devices simultaneously, total bandwidth is shared across the PCIe 3.0 x4 link (approx. 3.9GB/s), so peak speeds may be lower