This article covers StarTech.com 2ポートUSB-A増設PCI Expressインターフェースカード.

Overview

The StarTech.com PEXUSB312A3 is a PCI Express expansion card that adds two high-speed USB-A 3.2 Gen 2 (10Gbps) ports to any desktop PC. Powered by the ASMedia ASM3142 controller over a PCIe 3.0 x4 interface, it delivers full 10Gbps bandwidth per port. This card is an ideal solution for older systems lacking modern USB speeds or for users who have run out of rear-panel ports. UASP support further improves read/write performance with SSDs and fast flash drives.

Connectivity & Compatibility

The card uses a PCI Express 3.0 x4 interface and is backward compatible with PCIe 2.0 slots, though full 10Gbps per port requires x4 Gen3 bandwidth. It ships with both standard and low-profile brackets, making it suitable for full-size towers as well as compact SFF cases. Operating system support spans Windows (driver auto-install from Windows 8 onward), macOS, and Linux. A SATA power connector provides auxiliary power to the ports (up to 4.5W per port) when the PCIe slot alone cannot supply enough current, ensuring stable operation even with power-hungry devices.

Product Info

Launched around 2021, the PEXUSB312A3 is the direct upgrade over StarTech's popular PEXUSB312A2. It sits in the mid-range segment of the interface-card market, offering a balance of performance, reliability, and cost. The card is backed by a lifetime warranty and free technical support in Japan. Pricing hovers around ¥5,000, which is competitive for a two-port 10Gbps USB card with UASP and low-profile support.

Best Use Cases

  • Desktop users with NVMe SSDs or fast USB drives: UASP allows you to saturate the 10Gbps link, making backups and large-file transfers noticeably faster than older USB 3.0 (5Gbps) ports. - DIY builders needing extra USB-A ports: If your motherboard lacks enough rear USB ports, this card adds two internal high-speed ports without using external hubs. The included low-profile bracket means it fits in Mini-ITX builds too. - Legacy PC owners: Instead of replacing the entire motherboard, a single PCIe slot grants your older machine modern USB 3.2 Gen 2 speeds at a fraction of the upgrade cost.

Product Disclosure (Amazon)

  • Manufacturer: StarTech.com(スターテック)
  • Seller: Startech Japan KK
  • Fulfilled by: Amazon
  • ASIN: B08VNSK8HW
  • Note: This article covers a manufacturer-made product based on Amazon listing details.