StarTech has released a new Thunderbolt 3 USB hub that features three dedicated USB controllers and provides up to 20 Gbps of aggregated bandwidth to USB devices. The company aims the device at users of various bandwidth-demanding professional equipment that uses a USB 3.1 Gen 1 or Gen 2 interface. Since we are dealing with a device for specialized equipment, its price appears to be rather high.

StarTech’s Thunderbolt 3 to USB 3.1 Controller Adapter (TB33A1C) is based on Intel’s JHL6540 TB3 controller (Alpine Ridge, so it cannot work with USB 3.1 Gen 2 Type-C hosts) and is outfitted with two ASMedia’s ASM1042A (PCIe 2.0 x1 to USB 3.0) ICs and one ASM1142 (PCIe 3.0 x1 to USB 3.1 Gen 2) USB controller to ensure maximum performance for its ports.

The USB hub features one USB 3.1 Gen 2 Type-C, one USB 3.1 Gen 2 Type-A, and two USB 3.1 Gen 1 ports, with oneof the Gen 1 ports supporting the USB Battery Charging 1.2 spec. In addition, the hub has two Thunderbolt 3 port to support daisy chaining or to connect another USB 3.1 Gen 2 device. The hub also comes with a power brick that can deliver 65 W of power to host laptop via a TB3 interface, or USB devices that need more than 15 W provided by Thunderbolt 3 ports by default.

The aggregate bandwidth guaranteed by the StarTech Thunderbolt 3 to USB 3.1 controller adapter is 20 Gbps, and for people who need to ensure that they have the highest USB performance possible on their TB3-only laptops this is its key value (enabled by three USB controllers and multiple ports). There is a catch though. In order to connect two USB 3.1 Gen 2 devices at ~10 Gbps each one will have to use one of the USB 3.1 Gen 2 ports and the second TB3 port, but not both USB 3.1 Gen 2 ports. This is because both Gen 2 ports share one ASM1142 controller and the aggregate bandwidth it supports is limited to 8 ~ 10 Gbps (depends on its implementation) for both headers.

The StarTech Thunderbolt 3 to USB 3.1 Controller Adapter at a Glance
Controller Intel JHL6540 ASMedia ASM1142 2 × ASMedia ASM1042A -
Port 2 × Thunderbolt 3 1 × USB-C 3.1 Gen 2
1 × USB-A 3.1 Gen 2
2 × USB-A 3.1 Gen 1 20V/1.35A DC-IN
Bandwidth 40 Gbps 10 Gbps 5 Gbps + 5 Gbps -
Notes To connect two USB 3.1 Gen 2 devices at ~10 Gbps each, a USB 3.1 Gen 2 header and the second TB3 connector have to be used. Can be used to charge laptop or USB devices

StarTech positions this TB3 USB hub for connecting various bandwidth-demanding devices, such as 3D scanners, storage arrays, audio-video capture, and broadcast equipment. To guarantee their fast and flawless operation, the adapter features maxed-out USB bandwidth, which comes at a price. The Thunderbolt 3 to USB 3.1 Controller Adapter is available for $199.99 from Amazon, and for $263.99 directly from the manufacturer. is one of the leading suppliers of various adapters and hubs, so it is not surprising that it is gradually expanding its collection of Thunderbolt 3 products with new adapters for customers requiring very specific needs. The Thunderbolt 3 to USB 3.1 Controller Adapter is clearly one of such products that is not designed for everyone, but for people who need USB bandwidth to connect high-end scanners, storage arrays (or external SSDs), A/V, and broadcast equipment. Such clients demand maximum performance and are generally used to significant investments in hardware.

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Source: StarTech

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  • repoman27 - Monday, April 16, 2018 - link

    "...the aggregate bandwidth it supports is limited to 8 ~ 10 Gbps (depends on its implementation)..."

    Naw, due to 8b/10b encoding for PCIe 2.0 vs 128b/130b encoding for PCIe 3.0, the channel capacity is 8 Gbit/s or 7.877 Gbit/s. And we can probably assume that the three xHCI chips are connected as PCIe 2.0 x1, x1, and x2, so the ASM1142 would have an 8 Gbit/s connection.

    This is a confused and idiotic product. If your target market is people willing to spend $200+ for maximum bandwidth, then why didn't they go with a pair of ASM1142's? All of the ports would have then supported either 5 Gbit/s or 10 Gbit/s USB 3.1 operation. And I can't think of any USB Type-A thumb drives or devices with captive Type-A cables that would actually benefit from a 10 Gbit/s connection, so this is actually a reasonable scenario to go all-in on Type-C. The arbitrary mix of Type-A and Type-C is detrimental here; 2x Thunderbolt 3 and 4x USB 3.1 Type-C would have been better.

    Furthermore, at this price, all of the ports should support the latest USB Battery Charging and Power Delivery specs. Then the power brick could be USB Type-C as well. Heck, throw on a seventh Type-C port just for PD if you don't want to sacrifice any of the data ports for power.
  • joevt - Saturday, May 26, 2018 - link

    The ASM1142 can operate at PCIe 3.0 x1 (8 GT/s @ 128b/130b = 7.877 Gbps, 984.6 MB/s) or PCIe 2.0 x2 (5 GT/s @ 8b/10b = 8 Gbps, 1000 MB/s).

    USB 10 Gbps @ 128b/132b = 9.697 Gbps, 1212 MB/s). Flow control, packet framing and protocol overhead might reduce that to below even the max allowed by PCIe 3.0 x1?

    They could have used four ASM1142 (without using a PCIe switch) to provide 8 ports of USB 3.1 gen 2, but pairs of ports would be limited by the PCIe 3.0 x1 max (984 MB/s) and all ports would be limited to the Thunderbolt 3 max (2750 MB/s?). These limitations generally won't be a problem because all ports will likely not be used at the same time (unless some kind of USB raid is created?).
  • noblemo - Sunday, August 12, 2018 - link

    Aggregate bandwidth for the device is limited to 20 Gbps according to the manufacturer's website. I would like an adapter that provides 40 Gbps Thunderbolt 3 to 4-port x 10 Gbps USB 3.1 Gen 2. This StarTech unit could potentially work if the two Thunderbolt ports support USB-C 3.1-G2, but the 20 Gbps total data rate is disappointing.

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