StarTech.com

StarTech USB 2.0 to Gigabit Ethernet NIC Network Adapter (USB21000S2)

Name: StarTech USB 2.0 to Gigabit Ethernet NIC Network Adapter (USB21000S2)
Brand: StarTech.com
SKU: B007U5MGDC

Bottom line: The StarTech.com StarTech USB 2.0 to Gigabit Ethernet NIC Network Adapter: Adds Gigabit RJ45 to any USB 2.0 machine with no expansion slot or PSU needed; main trade-off: USB 2.0 host bus caps throughput at 480 Mbps, so gigabit speed is never reached.

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By Mike Perry, Founder & Editor-in-Chief · Listing data updated 2026-10-21

Mike Perry — Hardware researcher since 2014. For retro PC hardware and period-correct parts, synthesises manufacturer documentation, community compatibility lists and marketplace listings rather than first-hand lab testing. Core beat: GPU performance across gaming, rendering, and local-LLM inference. About the author →

Pros & Cons

Pros

✓ Adds Gigabit RJ45 to any USB 2.0 machine with no expansion slot or PSU needed
✓ Bus-powered over USB, no wall wart or extra cable to carry
✓ Jumbo Frame support up to 9 KB for large file transfers on the LAN
✓ NDIS 6.2 Checksum Offload (IPv4/IPv6/TCP/UDP) plus Large Send Offload cuts CPU load
✓ Backed by StarTech 2-year warranty and free lifetime technical support

Cons

✗ USB 2.0 host bus caps throughput at 480 Mbps, so gigabit speed is never reached
✗ Driver install may be required on older systems rather than pure plug-and-play
✗ Occupies a USB port continuously, a real cost on retro machines with only two

SpecPicks Verdict

SpecPicks scored StarTech.com StarTech USB 2.0 to Gigabit Ethernet NIC Network Adapter using a rating × review-volume × price-fit model applied to published specs and reviews across the retro networking cards category. StarTech.com's retro networking cards lineup sits within the broader category mid-tier; price and specs are the deciding factors over brand loyalty here. Judge it on the specification table and the price rather than on sentiment: check the figures that decide your use case, then put it side-by-side with two or three close alternatives in the Compare tool before clicking through.

Common buyer scenarios for retro networking cards of this kind: matching it to an existing build, replacing a failing part, or upgrading from a previous-generation equivalent. Check the spec table below against your current setup — particularly socket / form-factor / power-rating fields — and confirm compatibility on the retailer's listing before purchase. Prices and stock are set by the retailer and may have moved since this page was last updated.

Key Features

Compatible with Gigabit Ethernet networks and powered via USB for versatility and portability as an add-on or replacement
The Gigabit USB adapter helps conserve system resources, using built-in NDIS6 Checksum and Large Send Offload support and Jumbo Frames
The USB Gigabit Ethernet adapter is backed by a StarTech 2-year warranty and free lifetime technical support, ensuring reliability
USB to RJ45 adapter supports Gigabit networking over USB 2.0 with up to 480 Mbps of bandwidth
IEEE 802.3, 802.3u and 802.3ab (10BASE-T, 100BASE-TX, and 1000BASE-T) compatible
Jumbo Frame support up to 9 KB

Full Specifications

Brand	StarTech.com
Color	Black
Unit Count	1 Count
Connectivity	USB
Model Number	USB21000S2
Mfr Part Number	USB21000S2
Compatible Devices	Desktop
Data Link Protocol	Ethernet, Gigabit Ethernet, IEEE 802.1Q, IEEE 802.3
Data Transfer Rate	480 Megabits Per Second
Hardware Interface	Ethernet, USB 2.0
Warranty Description	2 year warranty
External Testing Certification	CE, FCC
Global Trade Identification Number	00065030847445, 00163120321131, 00778889503317

Ready to buy?

StarTech USB 2.0 to Gigabit Ethernet NIC Network Adapter (USB21000S2) is vintage hardware; the used and vintage market on eBay carries most of the live inventory. Prices and condition vary by seller and move in real time, so we link the live listing rather than quote a cached price. It also has an Amazon listing — check it for current price and availability. SpecPicks earns a small commission on qualifying purchases — thank you for supporting independent review work.

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