StarTech HB31C3ASDMB USB-C 10Gbps 3-Port Hub with SD/microSD Card Reader

Overview

The StarTech HB31C3ASDMB is a compact, bus-powered USB-C hub that expands a single USB Type-C port into three USB-A ports running at SuperSpeed 10Gbps (USB 3.1/3.2 Gen 2) while simultaneously adding an SD and microSD UHS-II card reader slot. At 2.5 oz with an aluminum and plastic build measuring 1.8 in long and 0.6 in tall, it sits flat on a desk or travels in a laptop bag without adding meaningful weight. The 9.8-inch host cable gives enough reach to connect cleanly without pulling at the port. No external power brick is required — the hub draws everything it needs from the host USB-C port, which keeps the setup clean for mobile workstations, security integration laptops, or field-deployment kits where outlet access is limited.

Key Features

• 10Gbps USB 3.1/3.2 Gen 2 throughput: Each of the three USB-A ports operates at up to 10Gbps, double the 5Gbps ceiling of USB 3.0/3.1 Gen 1. When offloading large video clips from a body-worn camera or transferring firmware packages to devices in the field, that bandwidth gap is tangible — a 10GB file that takes roughly 45 seconds at Gen 1 speeds moves in half the time at Gen 2.
• UHS-II SD and microSD card reader: UHS-II supports theoretical transfer rates up to 312MB/s versus 104MB/s for UHS-I. If you are pulling 4K footage from a UHS-II SD card, the reader won't be your bottleneck — the card's rated speed is preserved rather than throttled. Both standard SD and microSD are supported without an adapter, which matters when dealing with multiple camera formats on the same bench.
• Three USB-A ports at full Gen 2 speed: Ports are individually addressable at Gen 2 — bandwidth isn't pooled at a lower tier. Connect a USB storage drive, a configuration dongle, and a peripheral simultaneously without sacrificing throughput on any single port.
• Bus-powered operation: No AC adapter, no USB power brick. The hub draws power entirely from the host USB-C connection. This simplifies deployment in field kits, temporary surveillance setups, and mobile workstations where managing additional power cables adds complexity. Confirm your host port can deliver sufficient bus power before deploying with high-draw devices on all three ports simultaneously.
• 9.8-inch attached host cable: The fixed cable is long enough to clear most laptop edge ports without stress, but short enough that it won't create cable management issues on a tidy desktop. It eliminates the loose-connector reliability issues that come with a separate stub cable.
• Aluminum and plastic construction, 2.5 oz: The aluminum shell manages heat from the Realtek RTS5420 and RTS5329 chipsets while keeping the unit light enough for daily carry. Operating temperature is rated 0°C to 50°C, appropriate for office and light industrial environments — not for extreme cold or direct outdoor exposure.
• Broad backward compatibility: The HB31C3ASDMB is compatible with USB 3.0, USB 2.0, and USB 1.1 devices. Older peripherals connect and function at their native speed without requiring a separate hub or adapter.

Integration and Compatibility

The hub connects to any host with a USB Type-C port that supports USB 3.1 Gen 2 data transfer. Compatible hosts include current-generation Windows and macOS laptops, USB-C equipped workstations, and single-board computers used in edge deployment scenarios. The USB-A ports accept any USB-A device — storage drives, card programmers, serial adapters, or USB-licensed dongles common in security software environments. Because this is a USB hub rather than a docking station, it passes data only — no DisplayPort Alt Mode video output or power delivery passthrough. If you need video output or laptop charging through the same connector, a USB-C docking station is the appropriate solution instead. The UHS-II card reader is recognized natively by Windows and macOS without additional drivers in most configurations, making it straightforward to integrate into existing field workflows for surveillance camera footage review and card management. For a broader look at how peripheral connectivity fits into mobile security deployments, the field deployment connectivity guide covers host interface selection in more detail. The StarTech accessory line includes a range of USB-C connectivity solutions that pair well with this hub for more complex bench or field configurations.

Frequently Asked Questions

Q: Does the HB31C3ASDMB require an external power supply?

A: No. The HB31C3ASDMB is fully bus powered, drawing all operating power from the host USB-C port. No external AC adapter or power brick is needed. Be aware that connecting high-draw USB devices to all three ports simultaneously may approach the available bus power limit depending on the host system.

Q: What is the warranty on the HB31C3ASDMB?

A: The HB31C3ASDMB carries a 2-year manufacturer warranty.

Q: Can the HB31C3ASDMB be used with USB-A host ports using an adapter?

A: The host connection is USB Type-C. Using a USB-C to USB-A adapter would reduce the connection to USB 3.0 or USB 2.0 speeds at best and is not a supported configuration for Gen 2 performance. The hub is designed for USB-C hosts.

Q: Does the card reader support both SD and microSD simultaneously?

A: The HB31C3ASDMB includes both an SD and a microSD slot. Based on available product specifications, check manufacturer documentation for confirmation of simultaneous dual-card read capability, as slot behavior can vary by chipset implementation.

Q: What operating temperatures is the HB31C3ASDMB rated for?

A: The rated operating temperature range is 0°C to 50°C (32°F to 122°F), suitable for office and light commercial environments. Storage temperature range extends from -20°C to 70°C.

Q: Is the HB31C3ASDMB compatible with older USB devices?

A: Yes. The hub is backward compatible with USB 3.0, USB 2.0, and USB 1.1 devices. Older devices will connect and operate at their native speed.

Jerry Tildsen

The spec that gets overlooked on the HB31C3ASDMB is the UHS-II card reader — not because card readers are rare, but because most compact hubs in this class include UHS-I slots that cap at 104MB/s, quietly bottlenecking transfers from higher-end UHS-II cards used in current-generation body cameras and action recorders. Pairing UHS-II with Gen 2 USB-C throughput on the same device means neither the host connection nor the reader is the constraint when you are pulling footage quickly in a time-sensitive review workflow.

Technical Highlights:

• 10Gbps Gen 2 across all three USB-A ports: Gen 2 doubles the bandwidth ceiling versus standard USB 3.0 — each port operates independently at up to 10Gbps, which matters when running storage and a dongle simultaneously without throttling either device.
• Realtek RTS5420 + RTS5329 chipset combination: The RTS5420 handles the hub switching while the RTS5329 manages card reader functions — purpose-built split rather than a single-function chip handling both, which keeps read performance stable when the USB ports are under simultaneous load.
• Operating range 0°C to 50°C, 0–95% non-condensing humidity: Suitable for climate-controlled server rooms, office environments, and field kits stored in vehicles — but this is not a hardened outdoor device, and humid tropical environments should be evaluated carefully against the non-condensing humidity spec.

Deployment Considerations:

• Bus-powered operation is clean for mobile deployments, but verify your host USB-C port's available bus current before attaching three high-draw devices — some ultrabooks limit bus power more aggressively than desktop workstations.
• At 1.8 in long and 2.5 oz, the hub is genuinely pocketable, but the fixed 9.8-inch cable means it occupies a small footprint in a bag — plan cable routing on cramped mobile carts or equipment cases accordingly.

The HB31C3ASDMB is a practical fit for security integration field kits and evidence review workstations where a technician needs fast card offload from multiple camera media formats alongside USB peripheral access — without adding a power adapter to the kit.