This article covers StarTech.com 4ポート増設PCI Expressインターフェースカード.

Overview

The StarTech.com PEXUSB312A2C2V is a PCI Express expansion card that adds four USB 3.2 Gen 2x1 (10Gbps) ports to a desktop PC. It features two USB Type-C ports and two USB Type-A ports, powered by dual ASMedia ASM3142 controllers, delivering up to 10Gbps per port. With UASP (USB Attached SCSI Protocol) support, it maximizes the performance of external SSDs and NVMe drives. This card is an ideal solution for users who need more USB ports or faster connectivity than their motherboard provides. It fits into a PCIe 3.0 x4 slot and includes a full-profile bracket. An auxiliary SATA power connector supplies up to 15W (5V/3A) via USB-C and 4.5W (5V/0.9A) via USB-A.

Connectivity & Compatibility

The PEXUSB312A2C2V works with any desktop or server that has a PCIe 3.0 x4 slot. It is backward compatible with PCIe 2.0, though performance will be reduced. Supported operating systems include Windows, Linux, and macOS; Windows 8 and later automatically install drivers. It supports USB 3.2 Gen 2x1 (10Gbps) and is fully backward compatible with USB 3.0 and USB 2.0 devices. The USB-C ports feature a reversible plug design for easy connection with modern peripherals.

Product Info

This card is positioned as a mid-to-high-end USB expansion solution for IT professionals and power users. It comes with a 2-year manufacturer warranty and free technical support in Japan. The market positioning is clear: it fills the gap when motherboard USB ports are insufficient in number or speed.

Best Use Cases

Creative professionals and video editors who frequently transfer large files to/from external SSDs or NVMe enclosures. UASP support provides significantly faster transfer speeds compared to traditional USB 3.0. Desktop users with limited motherboard USB ports, especially those using Mini-ITX or Micro-ATX builds where expansion is constrained. * Power users running multiple USB devices simultaneously (external HDDs, capture cards, VR headsets). The dual-controller design allocates independent bandwidth to each port, preventing bottlenecks.

Things to Consider

This card uses a full-profile bracket only; it will not fit in low-profile or small-form-factor cases. Verify your case's expansion slot type before purchase. For best performance, use a PCIe 3.0 x4 or higher slot; PCIe 2.0 slots will limit throughput. The auxiliary SATA power connector must be connected when using the USB-C port's 15W power delivery. Without it, port operation may become unstable. Competing products with similar ASM3142 controllers are available, offering different port counts or power delivery capabilities. Compare specifications and pricing to find the best fit for your needs.

Product Disclosure (Amazon)

  • Manufacturer: StarTech.com(スターテック)
  • Seller: RADICAL (インボイス対応/適格事業者)
  • Fulfilled by: RADICAL (インボイス対応/適格事業者)
  • ASIN: B099H4K4WZ
  • Note: This article covers a manufacturer-made product based on Amazon listing details.