This article covers StarTech.com LANアダプター.
Overview
StarTech's USB31000S2 is a USB 3.0 to 2.5 Gigabit Ethernet adapter designed to add a fast wired network connection to laptops and desktops lacking an integrated 2.5GbE port. Powered by the Realtek RTL8156 chipset, it supports NBASE-T technology, allowing you to achieve 2.5 Gbps over existing Cat5e cabling without needing to upgrade to Cat6a or fiber. The adapter automatically negotiates speeds down to 1 Gbps and 100 Mbps for full backward compatibility. Its compact form factor weighs only 40 grams, and the space gray finish blends well with modern ultrabooks and productivity notebooks. Bus-powered via USB, it requires no external power adapter, making it a truly portable networking upgrade.
Connectivity & Compatibility
The adapter features a USB 3.0 Type-A (USB 3.1 Gen1) interface and a single RJ45 port supporting 2.5GBASE-T, 1000BASE-T, and 100BASE-TX. It supports 9K jumbo frames and VLAN tagging, essential for advanced network configurations. Compatibility spans Windows 7 through 10, Windows Server 2008 R2 and later, Linux with LTS kernel 4.19+, and macOS 10.11 through 11. It also works under virtualization platforms such as VMware and Hyper-V. Note that connecting to a USB 2.0 port limits throughput to USB 2.0's 480 Mbps maximum. For full 2.5 Gbps performance, a USB 3.0 or higher port is required.
Product Info
Released around 2020, the USB31000S2 remains widely available. On Japan it is priced at approximately ¥6,361 (tax included), positioning it as a mid-range option among USB 2.5GbE adapters. StarTech offers a standard 2-year warranty. The package includes the adapter only along with a quick-start guide. Market positioning: solid mid-range — not the cheapest, but backed by a reputable brand with reliable chipset support.
Best Use Cases
This adapter is ideal for laptop users whose built-in Ethernet is limited to gigabit or slower — especially those with premium notebooks like the Lenovo ThinkPad X1 Carbon, Dell XPS, or HP EliteBook. It's also perfect for content creators and NAS users who frequently transfer large files and want to boost throughput without rewiring their infrastructure. If you already have an NBASE-T-capable switch, adding this adapter to a single client is a low-cost way to unlock 2.5 Gbps speeds. The ability to reuse existing Cat5e cabling makes it a practical upgrade for home offices and small studios.
Product Disclosure (Amazon)
- Manufacturer: StarTech.com(スターテック)
- Seller: Startech Japan KK
- Fulfilled by: Amazon
- ASIN: B07Z8S6PN4
- Note: This article covers a manufacturer-made product based on Amazon listing details.
