Not all USB speeds are created equal (and sure, the numbers complicate issues)

Abstract

There’s a wide range of USB codecs on the market, using totally different connectors, knowledge charges, and charging speeds. You’ll want to match like equipment to get probably the most out of your units.
The most important cut up is between USB-A and USB-C connectors, the latter normally enabling sooner knowledge and energy, although not all the time. Examine specs earlier than shopping for something.
The perfect USB format is USB 4 2.0, which peaks at 120Gbps and helps Thunderbolt 5. It is exceptionally uncommon, so you will most likely be fantastic with the bottom 40Gbps USB 4 spec.

The U in USB is meant to face for Common, but you would be forgiven for considering it was something however. Past utilizing totally different connector varieties, some USB codecs supply wildly totally different knowledge and charging speeds. Often, connections could even assist charging however not knowledge, or vice versa. You’ve got encountered that dilemma in the event you’ve tried to make use of wired CarPlay or Android Autoand did not plug into the only port marked for knowledge sync.

In case you’re having hassle sorting issues out, this information is supposed to be a fast and helpful primer — I am not going to enter extreme depth about every model of USB. In truth, the one main division you (normally) want to fret about is USB-A versus USB-C, until maybe you are a video editor or connecting an exterior graphics card. That’ll make extra sense in a couple of moments.

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USB 1.0/1.1

The start of the know-how

USB Implementers Discussion board / Pocket-lint

The unique model of USB dates again to 1996, and was restricted to a whopping 1.5 megabits per second (Mbps) of information and 0.5W of energy supply. Extra importantly, it launched the oblong USB-A (AKA Kind-A) connector sort, which continues to be in use as we speak.

You’ll be able to, in concept, plug a USB 1.0 peripheral into a contemporary laptop computer with none points.

Realistically, the oldest model of USB you are prone to encounter is 1.1. That upgraded knowledge to 12Mbps, and energy to 2.5W, ample to attach mice and keyboards. You would not need to cost a state-of-the-art smartphone utilizing this tech — it’d take over 5 and a half hours to fully replenish an iPhone 16 Pro.

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USB 2.0

The usual that refuses to die

A USB stick on an old wooden storage box.

That is the oldest format nonetheless in energetic use. Whereas its energy supply is capped at 2.5W in most circumstances, knowledge speeds rise to 480Mbps. That is much more cheap for exterior storage drives, or syncing cellular units, although file sizes have grown a lot over time that it most likely will not really feel prefer it. Definitely, you need to keep away from utilizing USB 2.0 to again up a contemporary pc — it could take over 9 hours to repeat a 2TB drive.

It is value noting that Apple nonetheless caps knowledge at 2.0 speeds typically, even when it is utilizing extra fashionable connector varieties.

Most USB 2.0 units depend on a USB-A connector, however a number of connector varieties blossomed out of the usual, together with Kind-B, Mini-A, Mini-B, Micro-A, and Micro-B. Though the primary three have fallen by the wayside, you would possibly nonetheless run into micro-USB ports in uncommon circumstances.

It is value noting that Apple nonetheless caps knowledge at 2.0 speeds typically, even when it is utilizing extra fashionable connector varieties. Particularly, I am considering of Lightning cables, and the USB-C ports on non-Professional iPhones. The Lightning format has been fully abolished from Apple’s latest merchandise as of 2025.

Five Lightning port cables in a row in different colors.

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USB 3.0

The brand new baseline, and a brand new connector

A red USB-C cable on an old cedar chest.

3.0 has principally supplanted 2.0 because the minimal customary, boosting energy to at the least 4.5W, and knowledge speeds of as much as 5 gigabits per second (Gbps). 5Gbps transfers could make an enormous distinction — that very same 2TB backup I discussed earlier would end in below an hour.

Virtually as important because the pace enhance is frequent assist for USB-C (AKA Kind-C). When you’ll nonetheless see 3.0 gear with USB-A connectors, USB-C is more and more de facto, each due to newer requirements and due to comfort. USB-C is reversible, that means there isn’t any fear a couple of cable failing to insert correctly. Many individuals complain that USB-A cables all the time appear to enter upside-down in your first attempt.

A white iPhone 16e getting charged over USB-C on a red gradient background.

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USB 3.1 and three.2

Ditching the separate energy cables

The most important factor in USB 3.1 is widespread assist for USB Energy Supply (a.okay.a. USB-PD). This unlocks way more juice than earlier codecs, at the least as much as 100W. That is sufficient to energy many laptops, and absolutely recharge telephones in lower than an hour, although PD is in the end held again by the capability of your machine, cable, and/or adapter setup. A 100W cable will not max out in the event you’re utilizing a 30W adapter, for instance.

USB 3.1 Gen 1 supplies knowledge speeds of as much as 5Gbps, whereas Gen 2 doubles issues to 10Gbps. Confusingly, USB 3.2 Gen 1×1 and Gen 2×1 have the identical cut up — it’s important to soar to Gen 2×2 to attain 20Gbps.

Merchandise with USB-PD 3.1 assist energy of as much as 240W, sufficient for some gaming laptops. I ought to add that in some instances, USB-PD 3.1 could be paired with USB 3.0 and even 2.0 knowledge speeds — however since USB-PD 3.1 launched in 2021, you will normally see it related to USB 3.1 or later.

All variations of USB-PD require USB-C.

A pair of gaming laptops, one showing Xbox PC Game Pass.

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USB 4 and 4 2.0

The perfect you may get for now

A Thunderbolt 5 cable. — Newswire / Pocket-lint

Newswire / Pocket-lint

This is not as frequent correctly, however adoption is rising, and at this stage I would not purchase a brand new PC or Mac with out at the least one USB 4 connection. Usually, the usual helps transfers as much as 40Gbps, which is nearly a should in the event you’re doing 4K video modifying. Returning to that 2TB backup instance, a USB 4 configuration would possibly full the method in lower than seven minutes. USB-PD is assumed right here.

USB 4 contains Thunderbolt compatibility by default.

Even higher, USB 4 contains Thunderbolt compatibility by default. That is a typical utilized by a lot of high-speed equipment, although most often you are going to encounter Thunderbolt docks, which develop port choices with minimal congestion. {Hardware} makers are likely to at the least supply Thunderbolt 4, which absolutely exploits that 40Gbps capability. It is sufficient bandwidth to deal with two 4K60 DisplayPort screens concurrently.

On the slicing fringe of the trade is USB 4 2.0 (AKA USB 4 v2). Usually, this peaks at 80Gbps, however it will probably obtain 120Gbps if knowledge in a single route is proscribed to 40Gbps. It is also required to squeeze probably the most out of Thunderbolt 5.