UK What Gen 1 and Gen 2 mean
USB 3.2 Gen 1 and USB 3.2 Gen 2 are two speed grades of the same USB 3.2 specification, published by the USB Implementers Forum (USB-IF). Gen 1 signals at 5 Gb/s and Gen 2 at 10 Gb/s over a single lane. A third grade, Gen 2×2, runs two 10 Gb/s lanes together for 20 Gb/s.
The confusion comes from the names. Each new release of the specification absorbed the older speeds and renamed them, so the port sold as USB 3.0 in 2008 is the one now called USB 3.2 Gen 1. Nothing about the port changed; only the label did. To cut through it, USB-IF now asks makers to label ports by speed: USB 5Gbps, USB 10Gbps and USB 20Gbps.
The speed grade is also separate from the connector. A USB-C port can be Gen 1, Gen 2 or Gen 2×2, and a USB-A port can be Gen 1 or Gen 2.
USB 3.2 Gen 1, Gen 2 and Gen 2x2 compared
The table maps each grade to its old name, its new label and what it delivers in practice. Real-world figures are typical sequential transfers with a fast drive at both ends.
| Name | Former names | USB-IF label | Signalling rate | Lanes | Connectors | Typical real-world transfer |
|---|---|---|---|---|---|---|
| USB 3.2 Gen 1 | USB 3.0, USB 3.1 Gen 1 | USB 5Gbps | 5 Gb/s, 8b/10b encoding | 1 | USB-A, USB-B, Micro-B, USB-C | Around 400–450 MB/s |
| USB 3.2 Gen 2 | USB 3.1, USB 3.1 Gen 2 | USB 10Gbps | 10 Gb/s, 128b/132b encoding | 1 | USB-A, USB-C | Around 900–1,100 MB/s |
| USB 3.2 Gen 2×2 | None (new in 2017) | USB 20Gbps | 2 × 10 Gb/s, 128b/132b encoding | 2 | USB-C only | Around 1,700–2,000 MB/s |
Gen 2 is more than twice as fast as Gen 1 in practice because it changed the line code as well as the clock. Gen 1 uses 8b/10b encoding, which spends 20% of the bits on overhead, while Gen 2 moved to 128b/132b with about 3% overhead.
How USB 3.0 became USB 3.2 Gen 1
The renaming happened in three steps, and older datasheets still use every one of the names. When you compare two products, convert both to a speed first.
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2008: USB 3.0. SuperSpeed USB at 5 Gb/s, with blue USB-A inserts and extra contacts behind the USB 2.0 pins.
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2013: USB 3.1. USB 3.0 became USB 3.1 Gen 1, and the new 10 Gb/s mode was USB 3.1 Gen 2, marketed as SuperSpeed+.
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2017: USB 3.2. Both were renamed again, to USB 3.2 Gen 1 and Gen 2, and two-lane modes were added for USB-C, including Gen 2x2 at 20 Gb/s.
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2022 onwards: speed labels. USB-IF dropped the version numbers from packaging and logos in favour of USB 5Gbps, USB 10Gbps and USB 20Gbps.
Cables, connectors and compatibility
Every USB 3.2 grade is backward compatible. A Gen 2 device works in a Gen 1 port and a Gen 1 device works in a Gen 2 port, and the link always runs at the speed of the slowest part: the port, the cable or the device.
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The cable matters at 10 Gb/s. A cable rated for USB 3.2 Gen 1 may not hold a reliable Gen 2 link. Look for a 10 Gb/s rating, and for Gen 2x2 a full-featured USB-C cable at both ends.
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Passive cables are short. The USB Type-C specification expects passive cables of up to about 2 m for Gen 1 and about 1 m for Gen 2. Longer runs need active or optical cables.
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USB 2.0 cables cap the speed. A charge-only or USB 2.0 cable drops any USB 3.2 device to 480 Mb/s, and some will not carry data at all.
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Gen 2x2 needs USB-C at both ends. It uses both pairs of high-speed lanes in the USB-C connector, so it cannot run through USB-A or through an adapter.
Which grade an industrial system needs
On industrial and embedded computers, most rear-panel USB 3 ports are Gen 1 or Gen 2, and Gen 2×2 is uncommon. Gen 1 is enough for barcode scanners, touch controllers, licence dongles and most machine vision cameras built to the USB3 Vision standard, which was designed around 5 Gb/s. Gen 2 earns its place for external NVMe storage, offloading logged data and capturing uncompressed 4K video through USB frame grabbers.
Bandwidth is shared more often than people expect. Several ports on one embedded box PC may sit behind a single controller or hub, so two cameras on adjacent ports can split one 5 Gb/s link. For multi-camera systems, check how the ports map to controllers before you plan the wiring, or move to USB4 or Ethernet cameras. Our USB4 explainer covers the 40 Gb/s generation, and our white paper on industrial USB applications covers locking connectors and cable runs on the factory floor.
USB 3 signalling also produces noise around 2.4 GHz, which can degrade nearby 2.4 GHz Wi-Fi and wireless receivers. Shielded cables and keeping dongles away from USB 3 ports usually solve it.
Quick answers on USB 3.2 Gen 1 vs Gen 2
USB 3.2 Gen 1 vs Gen 2: common questions
Is USB 3.2 Gen 1 the same as USB 3.0?
Yes. USB 3.2 Gen 1, USB 3.1 Gen 1 and USB 3.0 are three names for the same 5 Gb/s interface. Only the label changed between releases of the specification.
Is USB 3.2 Gen 2 the same as USB 3.1?
Yes, as USB 3.1 Gen 2. The 10 Gb/s mode introduced in USB 3.1 was renamed USB 3.2 Gen 2 in 2017. Products described simply as “USB 3.1” are usually Gen 2, but check the speed.
Is USB 3.2 Gen 2 faster than Gen 1?
Yes, about twice as fast. Gen 2 signals at 10 Gb/s against 5 Gb/s, and its lower encoding overhead means real transfers often run a little over double, provided the device and cable can keep up.
Can I plug a Gen 2 device into a Gen 1 port?
Yes. It works at Gen 1 speed. The same applies the other way round: a Gen 1 device in a Gen 2 port runs at 5 Gb/s.
Do I need a special cable for USB 3.2 Gen 2?
Usually a 10 Gb/s rated one. A USB 3 cable rated for 10 Gb/s, kept to about 1 m for passive USB-C, gives a reliable Gen 2 link. A USB 2.0 cable limits the connection to 480 Mb/s.
Is USB 3.2 the same as USB-C?
No. USB 3.2 is the data standard and USB-C is the connector shape. A USB-C port might run USB 2.0, any USB 3.2 grade, USB4 or Thunderbolt.
We specify the USB controllers, port layout and cables for each industrial computer we build, and fit and test cameras, capture devices and storage as standard. Tell us what will plug in and how far away it sits, and we will match the ports to it.