This article covers StarTech.com 2ポートUSB Type-C増設PCI Expressカード USB 3.1 Gen 2(10Gbps)準拠 PCIe Gen 3 x4対応 PEXUSB312C3 [並行輸入品].

Overview

The StarTech.com PEXUSB312C3 is a PCI Express add-on card that adds two USB Type-C ports to your desktop PC. It supports USB 3.1 Gen 2 at 10Gbps, making it an excellent choice for users who need fast connectivity for external SSDs, high-speed flash drives, or other USB-C peripherals. The card uses a PCIe Gen 3 x4 interface, ensuring enough bandwidth for simultaneous high-speed transfers, and supports UASP (USB Attached SCSI Protocol) to reduce CPU overhead and improve transfer efficiency. A dual-profile design allows the card to fit both standard and low-profile cases, and an optional SATA power connector provides extra juice for power-hungry devices. This combination of speed, compatibility, and power flexibility makes the PEXUSB312C3 a versatile upgrade for any desktop system lacking native USB-C ports.

Connectivity & Compatibility

Interface: PCI Express Gen 3 x4 (works in x4, x8, x16 slots) Ports: 2 x USB Type-C (USB 3.1 Gen 2, 10Gbps) OS Support: Windows, Linux (driverless with in-box drivers) Power: Optional SATA power connector for high-power devices * Form Factor: Standard and low-profile (bracket included) For best performance, connect USB 3.1 Gen 2 devices. If your PCIe slot is Gen 2 or older, bandwidth may be limited. The card is backward compatible with USB 3.0/2.0 devices, but speeds will drop accordingly.

Product Info

Released around 2020, the PEXUSB312C3 remains a popular choice for adding USB-C to older or budget PCs. Pricing hovers around ¥8,000 (≈$55) on Japan, placing it in the mid-range for two-port USB-C cards. The card comes with a low-profile bracket, driver disc (usually unnecessary), and manual. Warranty is typically 2 years from StarTech. Market positioning: entry-to-mid tier. While faster USB 3.2 Gen 2×2 cards exist at higher prices, the PEXUSB312C3 offers a proven, stable 10Gbps solution with UASP support that delivers real-world speeds close to the theoretical limit.

Best Use Cases

Desktop users lacking USB-C ports: Ideal for motherboards with few or no USB-C connectors, especially when front-panel headers are unavailable. Frequent external SSD users: The 10Gbps bandwidth significantly reduces transfer times for large files, backups, or media editing workflows. Low-profile PC builders: The included low-profile bracket makes it easy to install in compact cases like HTPCs or small form-factor systems. Users with power-hungry USB-C peripherals: The optional SATA power connector ensures stable operation for devices like USB-C hubs, external displays, or high-speed storage enclosures.

Product Disclosure (Amazon)

  • Manufacturer: StarTech.com(スターテック)
  • Seller: Startech Japan KK
  • Fulfilled by: Amazon
  • ASIN: B087G7T234
  • Note: This article covers a manufacturer-made product based on Amazon listing details.