USB Speed Table
| Version | Year | Max rate | Note |
|---|---|---|---|
| USB 1.0 | 1996 | 1.5 / 12 Mbit/s (LS / FS) | First official spec |
| USB 1.1 | 1998 | 1.5 / 12 Mbit/s | Errata cleanup |
| USB 2.0 | 2000 | 480 Mbit/s (HS) | The decade-defining upgrade |
| USB 3.0 | 2008 | 5 Gbit/s | SuperSpeed, dual-bus design |
| USB 3.1 Gen 2 | 2013 | 10 Gbit/s | SuperSpeed+ |
| USB 3.2 Gen 2x2 | 2017 | 20 Gbit/s | Two 10G lanes |
| USB4 | 2019 | 40 Gbit/s (Gen 3x2) | Thunderbolt 3 protocol base |
| USB4 v2 | 2022 | 80 Gbit/s (or 120/40) | Symmetric/asymmetric modes |
USB speeds double every generation since 2008, and the table traces the whole climb: 1.5 Mbit/s Low Speed and 12 Mbit/s Full Speed in USB 1.0 (1996), the 480 Mbit/s High Speed of USB 2.0 (2000) that defined a decade, 5 Gbit/s SuperSpeed in USB 3.0 (2008), then 10, 20, 40 and 80 Gbit/s as USB 3.1, 3.2 and USB4 doubled their way through 2013 to 2022. Reading it as one line explains every cable you own: the numbers are backward-compatible ceilings, so a USB4 port still talks to a 1998 mouse at Full Speed.
The confusing part is not the speeds but the names, and the blame lands on a 2019 rebrand: USB-IF renamed USB 3.0 to USB 3.2 Gen 1, USB 3.1 Gen 2 became USB 3.2 Gen 2, and the marketing labels (SuperSpeed, SuperSpeed+, then just speed numbers on packaging) changed around them. Practical decoding rules: Gen 1 means 5 Gbit/s, Gen 2 means 10, the x2 suffix means two lanes running in parallel (doubling the rate: Gen 2x2 is 20), and USB4 dropped the pretense of new names by keeping lane-count labels like Gen 3x2 while jumping to 40 and 80 Gbit/s. When a box says nothing at all, color and logo are the fallback - and neither is standardized, which is exactly why the table is worth bookmarking.
How to use
- Match the port to the need, not the year: 480 Mbit/s (USB 2.0) moves about 35 MB per second, fine for keyboards and slow backups; external SSDs want the 10 Gbit/s of USB 3.2 Gen 2 or better, or the drive is the bottleneck, not the disk.
- Decode any label with the Gen rules: Gen 1 = 5, Gen 2 = 10, x2 doubles via two lanes (Gen 2x2 = 20 Gbit/s), USB4 Gen 3x2 = 40, and the rare asymmetric Gen 4 mode swaps 120 one way against 40 the other for display-heavy setups.
- Remember the whole chain slows to its weakest link: a 10 Gbit/s drive on a 480 Mbit/s hub runs at hub speed - check the oldest component in the path before blaming the new device.
Frequently asked questions
What is the difference between USB 3.0, 3.1 and 3.2?
On paper: 3.0 is 5 Gbit/s (2008), 3.1 Gen 2 doubled it to 10 (2013), and 3.2 (2017) added the option of running two lanes in parallel - Gen 1x2 at 10 Gbit/s and Gen 2x2 at 20. In practice the names moved underneath the products: in 2019 the USB-IF rebranded 3.0 as USB 3.2 Gen 1 and 3.1 Gen 2 as USB 3.2 Gen 2, so a cable printed 3.2 Gen 1 is exactly a 2008-era 5 Gbit/s cable with newer ink. The marketing names shifted again as SuperSpeed, SuperSpeed 10Gbps, and then bare numbers on retail boxes. The defense is mechanical: read the Gen and lane labels against the table, ignore the era on the packaging - and remember that all of them are backward compatible, so the 3.2 cable works in the 2010 laptop, just at 2010 speed.
Why is my USB 3.x device only reaching USB 2.0 speeds?
Because one 480 Mbit/s link anywhere in the chain caps the whole path, and the suspects are ordered by likelihood: a USB 2.0 hub in the middle, a front-panel port wired for 2.0 on an otherwise fast motherboard, the wrong end of a mixed cable, or a drive enclosure whose bridge chip is genuinely 2.0 inside. The protocol negotiates to the lowest common denominator per link, not per port pair, so a single legacy hub silently downgrades everything behind it. Diagnosing takes one swap at a time - move the device to a known USB 3 port directly on the machine, replace the cable, remove hubs - and watching the negotiated rate on the operating system's USB tree. The 35-MB/s ceiling is the fingerprint of USB 2.0: if a big file transfer sits just under it, somewhere in the chain there is a 2000-era component.
Is USB4 the same as Thunderbolt?
They converged: USB4 (2019) is built on the Thunderbolt 3 protocol that Intel opened up, so a USB4 port at 40 Gbit/s carries the same tunneling architecture - data, display and PCIe traffic sharing one link - and Thunderbolt 3/4 devices work in USB4 hosts that support the optional features. The differences live in the fine print: Thunderbolt 4 certification guarantees the optional pieces of USB4 (two 4K displays, PCIe tunneling at 32 Gbit/s, charging on the same port), while a bare USB4 port may omit them; and USB4 Version 2 (2022) pushed both families to 80 Gbit/s symmetric or 120/40 asymmetric, with Thunderbolt 5 following. For a buyer the practical rule holds: a Thunderbolt-certified cable and port are a guaranteed superset of USB4 basics, and any USB4 gear still negotiates politely with older USB devices down the table.
Why do speeds plateau at 480 Mbit/s on paper but transfer slower in reality?
The table rates the wire, not the payload: USB 2.0's 480 Mbit/s is the signaling rate, and the protocol's overhead - packet framing, polling intervals, the bulk-transfer handshakes - eats roughly half of it, landing real-world throughput near 35-40 MB/s on a good day. USB 3.x widened the gap differently: its 5 and 10 Gbit/s links use 8b/10b and 128b/132b encoding plus fresh framing, so real speed tracks the line rate much closer (about 450 and 1000 MB/s respectively), but the storage device itself then becomes the limit - a spinning drive tops out near 120 MB/s no matter what cable you feed it. That is why the honest shopping math is: read the table for the port class, halve USB 2.0 numbers by reflex, and check the drive's own rated speed before attributing slowness to the cable.