USB c charging specification. Next up: USB4

USB-C explained: How to get the most from it (and why it still keeps getting better)

Now that you’re used to seeing co-workers, family, and strangers on planes use the oblong USB-C connector, it’s time to see just what this promising standard is capable of. As we approach its eighth birthday, the USB-C plug is now part and parcel of most current laptops, phones, and tablets. Even MacBooks, iPads, and Chromebooks are moving to USB-C.

In other words, we are well into the USB-C era, and the older rectangular USB Type-A plug we are so used to is slowly going the way of the dinosaur.

This evolution is happening faster in some arenas than others. For example, the latest Mac Studio desktop has no fewer than six USB-C ports, four of which are top-speed Thunderbolt 4 connections. On the other hand, Apple iPhones are stubbornly clinging to the company’s proprietary Lightning connector.

What is USB-C?

USB Type-C, commonly referred to as USB-C, is becoming the standard connector for moving data and power to and from a wide variety of computing devices. Its symmetrical design means it can be inserted either way — up or down — eliminating many of the frustrations of earlier USB ports and putting it on a par with Apple’s reversible Lightning plug.

This alone makes it a hit for me. But USB-C continues to evolve toward faster data transfers and the ability to push more power to devices. And it’s closely linked to several powerful new technologies, including Thunderbolt and USB Power Delivery, that have the potential to change how we think about our gear and how we work in the office, on the road, and at home.

There is a dark side, though. USB-C is just the connector type; it’s built on the Universal Serial Bus specification, and that’s where things get messy. The four main USB protocols in use today are confusing, to say the least, creating an alphabet soup of standards that could muddle the most technical among us. Here is a breakdown of the specifications:

  • Today, the most popular USB spec is the USB 3.2 Gen 1 protocol. It allows a maximum throughput of 5Gbps to travel over a single lane of data and can use an old-school Type-A rectangular plug or the oblong USB-C connector.
  • The next step up in speed bifurcates into two alternatives: the use of double speed lanes of data that abide by the old speed limit (USB 3.2 Gen 1×2) or a single lane that operates at twice the speed (USB 3.2 Gen 2×1). Either way, the result is 10Gbps peak throughput.
  • The most recent update is the USB 3.2 Gen 2×2 protocol, which uses two lanes of double-speed data traffic to top out at 20Gbps.

Confusing matters more, the USB 3.2 single-lane protocols are basically renamed USB 3.1 protocols, which you may still see on some devices. USB 3.1 Gen 1 is the same as USB 3.2 Gen 1, and USB Gen 3.1 Gen 2 is the same as USB 3.2 Gen 2×1.

The USB Implementers Forum (USB-IF), the organization that develops and governs the USB standard, suggests that device makers use its “SuperSpeed USB” designations (see table below) to simplify marketing to consumers, but manufacturers don’t always heed this advice. Bottom line: read the specs carefully.

What’s in a name? USB 3.2 specs and speeds

On the plus side, older devices do work with the newer specs. That two-year-old USB-C flash storage key will work with your newest laptop, although not always at top speed.

Fast data storage

The first generation of USB 3.2 Gen 2×2 storage devices is available now, including the SanDisk Extreme Pro Portable SSD. Aimed at storing the huge files that result from ultra-high-resolution photography, 4K videos, or machine learning files, the Extreme Pro is on the big side at 4.3 x 2.3 x 0.4 inches, but it can hold up to 4TB of data and encrypt files using the AES technique.

The mileage you get from a cutting-edge SSD like this depends on the system you plug it into. For example, I tried the Extreme Pro with my two-year-old HP 590 desktop PC running Windows 10 using’s USB 3.2 Gen 2×2 PCI-Express card Remove non-product link. and it delivered an average of 11.3Gbps on the Passmark PerformanceTest Disk Mark Throughput tests. That isn’t quite the 20Gbps SanDisk promises but is still quite impressive. And, to be fair, the slowdown might be the result of my desktop PC’s older PCI-Express implementation. Even with that caveat, this was a threefold improvement over the 2.9Gbps I got from the Extreme Pro with my PC’s native USB 3.1 chip.

While the 4TB Extreme Pro drive Remove non-product link costs a startling 630, it’s also available in 1GB and 2GB sizes for 210 and 300 at publication time (may vary). There are other options in this category as well, including Samsung’s T7 Portable SSD Remove non-product link (115 for 1TB), PNY Technologies 4TB X-Pro Portable SSD Remove non-product link (580 for 4TB) and the WD Black P50 Game Drive SSD Remove non-product link (140 for 500GB).

Making USB-C work for you

To get the most out of these new specs, you’ll need to make some changes and buy some accessories. Your old USB gear should all still work, though, even if it can’t take advantage of the new speeds. I will help ease the transition by showing you what you can do with USB-C and what you’ll need to make it work.

Be careful, because not all USB-C devices support all the latest USB-C specs. For instance, just about every USB-C flash drive sold today supports the earlier USB 3.1/3.2 Gen 1 protocol, and some tablets and phones don’t support Alt Mode video. It’s best to read the spec sheet carefully so you know what you’re getting before you buy.

Here are some tools, tips, and DIY projects that will help you get the most out of USB-C.

Make a USB-C travel kit

The good news is that USB-C ports can be used with older USB 2, 3.0, and 3.1 accessories. The bad news is that you’ll need a drawer full of adapters and cables. So far, I haven’t seen anything close to a complete ready-made kit. So, I’ve made my own USB-C survival kit with six key cables and adapters in a zippered case.

  • Two small male USB-C to female USB Type-A adapters for connecting to older devices, such as flash drives.
  • A short adapter cable with a USB Type-A male plug on one end and a male USB-C on the other.
  • A USB-C AC adapter.
  • A USB-C male-to-male cable for using accessories.
  • A USB-C Ethernet adapter for when a wired connection is available.
  • An HDMI adapter for connecting two cables together.
  • A Baseus 8-in-1 USB C Hub Docking StationRemove non-product link that has three old-school Type-A USB 3.0 ports and one USB-C connector that can deliver up to 100 watts of power. The 40 hub also has a gigabit per second wired Ethernet port, slots for full-size SD cards and micro-SD cards, and an HDMI port that can feed 4K video to a display.
  • A small microfiber cloth for screen cleaning.

There’s one additional adapter I’ve found useful at home and on the road because, sadly, many Android phones and tablets now lack a headphone jack. I have USB-C earbuds but usually can’t find them when I need them. When that happens, I use a headphone jack adapter so I can use any inexpensive wired headphones with my Samsung Galaxy Note 20 phone. They cost about 10 each.

Make an inexpensive homemade SSD drive

There’s one more thing I take on the road: a homemade SSD drive that’s smaller than the SanDisk Extreme Pro but just as fast. I built it using the SIIG USB 3.2 Gen 2×2 Type-C 20G NVMe SSD Enclosure Remove non-product link. which has a name that’s a mouthful but at 4.9 x 1.7 x 0.5 inches fits easily in my travel bag. Using it to build my own drive was an excellent hack for a mobile storage system.

Here’s how I did it, sans tools.

Start with the drive, enclosure, and included cable.

Open the two thumbscrews at the enclosure’s end with the USB-C port and remove the black end plate.

Slide the enclosure’s cover off.

Align the SSD card with the enclosure’s connections, insert it, and slide the lever at the end to hold the module in place.

Install the included thermal pad, close the device up, and replace the two thumbscrews. Plug it into the computer, and the device’s small green LED lights up to show it’s connected.

charging, specification, usb4

Mine delivered an average of 11.3Gbps using my HP 590 desktop, according to PassMark PerformanceTest’s Disk Mark Throughput benchmark. Not bad for three minutes of work.

Set up a dock

Nothing says “welcome home” like a docking station on your desk that connects your laptop — and in some cases a tablet or phone — to your network connection, external drives, mouse and keyboard, and peripherals — all while charging your system. A good docking station can not only send video to a display but often create a multi-display array with two or three screens.

USB-C power upgrade to 240W could banish some of your proprietary chargers

As new USB standards catch on, choices for cables’ data rates and power levels will be less confusing, the USB industry group predicts.

Stephen Shankland has been a reporter at CNET since 1998 and writes about processors, digital photography, AI, quantum computing, computer science, materials science, supercomputers, drones, browsers, 3D printing, USB, and new computing technology in general. He has a soft spot in his heart for standards groups and I/O interfaces. His first big scoop was about radioactive cat poop.

  • I’ve been covering the technology industry for 24 years and was a science writer for five years before that. I’ve got deep expertise in microprocessors, digital photography, computer hardware and software, internet standards, web technology, and other dee

USB-C just got a power upgrade to 240 watts that’ll let you plug in devices like gaming laptops, docking stations and 4K monitors. By more than doubling power from today’s 100-watt top capacity, the new USB-C standard could eventually let you toss a lot of proprietary chargers into your junk drawer.

The USB Implementers Forum, the industry group that develops the technology, revealed the new power levels in the version 2.1 update to its USB Type-C specification on Tuesday. The new 240-watt option, called Extended Power Range (EPR), should arrive in devices in the second half of 2021, USB-IF said.

One hundred watts has served a lot of purposes, but there are markets that could benefit from more power.- things like gaming notebooks or maybe a docking station that can distribute more power to the things connected to it, said USB-IF Chairman Brad Saunders.

USB began as a useful but limited port for plugging keyboards, mice and printers into PCs. It later swept aside Firewire and other ports as faster speeds let it tackle more demanding tasks. It proved useful for charging phones as the mobile revolution began, paving the way for its use delivering power, not just data. The 240W Extended Power Range option means USB likely will expand its turf yet again.

You can charge everything from toothbrushes to power drills with USB today, and the increase in power could help USB become an ordinary way to supply power consumer electronics devices and many other products. In USB-IF’s vision, you can expect to see USB-C charging ports becoming ever more common on power strips, cars and power sockets on the wall, Saunders said.

Cables supporting 240 watts will have additional requirements to accommodate the new levels. And USB-IF will require the cables to bear specific icons so that end users will be able to confirm visually that the cable supports up to. 240W, USB-IF said in the specification document.

You can also expect a new look for lower-power cables, now called Standard Power Range, that will max out at 60W by delivering electrical current of 3 amps. Today’s higher-power cable products, which can carry up to 100W of power by using current up to 5 amps, will be replaced by EPR cables.

A capacity of 240 watts is enough to run larger monitors, workstations, gaming laptops and other devices. Dell’s UltraSharp 32-inch 4K monitor has a peak power usage of 230 watts, for example, the same level as HP’s 17-inch Omen gaming laptop. Also eligible are all-in-one computers like Apple’s iMac.- though that uses a proprietary power cord.

USB’s expanding utility

It isn’t, however, enough for everything. Try NewEgg’s power supply calculator to see how a gaming PC with a higher-end video quickly surpasses 240 watts. Laser printers can also draw a lot of power.

Several USB standards

USB-C is the relatively new variety of oval ports and reversible cables, a design that means you no longer have to worry which side is up on plugs. The design also means the same cable works on phones, tablets and PCs. The USB-C specification isn’t the only one covering how USB ports and cables work. Today’s mainstream USB 3.2 and brand-new USB 4 govern how data is sent over cables, while USB Power Delivery governs how devices negotiate with chargers and other devices.

The USB PD specification has been updated to version 3.1 to accommodate the 240W power level, USB-IF said.

USB’s new utility has come with growing pains. It can be tough to figure out if that USB-C cable you have lying around supports fast data rates or the highest power rating, and the more power cables carry, the more worried you’ll probably be about fried laptops.

But the USB standards have lots of protections, including negotiations between devices to make sure power stays at supported levels and electronic labels in the cables that tell devices how much electricity they can handle.

As the new USB standards mature and components become cheaper, the new power and data capacities will become commonplace, said USB-IF Chief Operating Officer Jeff Ravencraft. USB-IF doesn’t expect mainstream consumers to have to learn terms like EPR and SPR.

The general consumer has no clue about voltages and amps. Nobody understands any of this stuff, Ravencraft said. We’ll FOCUS on the brands we have for chargers, and we’re working on a way to identify to the consumer in very simple terms the support for this higher wattage cable.

Careful about cables

The power boost led the USB-IF to add a long section to the USB-C standard with advice about how manufacturers can prevent problems from electrical current arcing through the air between the USB-C plug and port when you unplug a device. But you can still expect some small zaps.

The goal of arcing mitigation is not necessarily to entirely prevent arcing but to prevent damage to the connector pins due to arcing that may still occur, the document said.

One port that USB hasn’t managed to displace is Intel’s Thunderbolt. With USB 4, it’s caught up to Thunderbolt’s 40Gbps speed by actually embedding Thunderbolt technology. The two standards continue to converge, though Intel maintains separate certification program for Thunderbolt.

But USB 4 is rare, just arriving now in newer laptops, and Thunderbolt offers some reliability advantages. Thunderbolt uses a laptop’s USB-C ports through a repurposing called alt mode, but not all USB-C ports support Thunderbolt.

Alt mode also can let you plug in external monitors’ HDMI and DisplayPort cables into USB-C ports. However, HDMI cables remain commonplace, and rumors suggest Apple could be restoring the HDMI port after years of offering only combination USB-C/Thunderbolt ports.

Is USB-C the Same as Micro USB or USB 3.0?

The USB-C connector looks similar to a micro USB or rectangular USB 3.0 connectors at first glance, though it’s more oval in shape and slightly thicker to accommodate its best feature: flippability.

Like Lightning and MagSafe, the USB-C connector has no up or down orientation. Line up the connector properly, and you never have to flip it over to plug it in; the right way is always up. The standard cables also have the same connector on both ends, so you don’t have to figure out which end goes where. That has not been the case with all the USB cables we’ve been using for the past 20 years. Most of the time, you have different connectors at each end.

USB-C and USB 3.2: The Numbers Beneath the Port

Where USB-C gets tricky is in the numbers that get attached to the ports. The most common speed that USB-C connectors are rated for is 10Gbps. (That 10Gbps is theoretically twice as fast as original USB 3.0.) USB-C ports that support this peak speed are called USB 3.2 Gen 1×2.

The minor wrinkle is that USB ports with 10Gbps speeds can also exist in the original, larger shape (the USB Type-A rectangles we all know), and are dubbed USB 3.2 Gen 2×1. With the exception of some desktops, though, it’s more common to see 10Gbps-speed USB ports with USB-C physical connectors. Note: Some older USB-C ports support just 5Gbps maximum speeds, so it’s important to look for a USB 3.2 Gen 1×2 or 10Gbps designation to verify that a given USB-C port supports 10Gbps transfers. That said, all of these ports are backward-compatible, just at the speed of the slowest element.

Confused yet? Further complicating matters: The number scheme around USB 3 has been in flux, which has made references to these ports something of a swamp. Until recently, many USB-C ports carried the USB 3.1 label (USB 3.2 was not yet a thing) in Gen 1 and Gen 2 flavors, and some spec sheets continue to reference the older name, along with SuperSpeed branding. In a confusing twist, the USB-IF decided to eliminate the use of USB 3.1 in favor of these various flavors of USB 3.2, as outlined below in this handy decoder chart.

The USB 3.2, USB 3.1, and SuperSpeed designations you see above on each line are equivalent, just differing in name. If you see a USB 3.1 label, it’s best to inquire about the maximum transfer speeds of the port directly with the device manufacturer or reseller.

As you can see above, some USB-C ports use the USB 3.2 Gen 2×2 specification, with maximum speeds of 20Gbps. The USB-IF decided on 2×2 because this standard doubles the data lanes within a USB-C cable to achieve the 20Gbps transfer speed. These ports have not been widely available. They will likely go by the wayside in favor of another emerging flavor of USB-C ports, supporting USB4, which the USB-IF has announced will eventually support data speeds up to 120Gbps.

To reduce confusion, the USB-IF also intends to do away with numbered USB versions in the future, instead encouraging device makers to refer to a port’s top speed, as in USB 20Gbps.

Can You Go From USB-C to DisplayPort?

You might think of your old USB Type-A port simply as a data port for connecting drives or peripherals like mice. But USB-C, depending on the specific port’s implementation, can do much more. One of USB-C’s most useful skills, when designed thus, is delivering enough power to charge the host device, such as a laptop or a smartphone. In fact, many lightweight laptops that have USB-C ports use them in place of a traditional barrel-style connector as the only option for attaching an AC adapter.

USB-C’s support for sending simultaneous video signals and power means that you might be able to connect to and power a native DisplayPort, MHL, or HDMI device, or connect to almost anything else, assuming you have the proper adapter and cables. (See below for more on adapters.) The USB-C spec even factors in audio transmissions over the interface, but so far it has not replaced the 3.5mm headphone jack on computers to the same degree as it has on phones and tablets.

Make sure to check the specs on any PC you’re thinking of buying, because not all USB-C ports are alike. So far, every one we’ve seen supports both data transfers and connected-device power delivery over USB-C (though not necessarily charging of the host device). But while the USB-C standard supports connecting DisplayPort and/or HDMI displays with an adapter (via the DisplayPort-over-USB protocol), not every PC maker has connected the ports to every system’s graphics hardware. Some USB-C ports on a system may support video-out connectivity, while others may not; or none may. And some devices add extra layers of security or other requirements to connect USB-C peripherals, including Macs, which requires user approval before the accessory can communicate starting with macOS 13 Ventura. Looking at the details is important.

How does USB-C Power Delivery Work?

The basic gist of how it works is that two USB-PD enabled devices negotiate a power contract, or a handshake, when they’re plugged into each other. They discuss how much power the source can support, as well as how much power the device being charged can handle. The standard for USB-C devices without PD is 5V/3A, but the voltage is configurable depending on the device and can go as high as 20V/5A (with an EMCA cable). Then they settle on a compatible rate which both the supply and device support and the charging (or discharging) begins.

It’s important to note that not all USB-C ports support USB-PD, nor will all USB-C devices charge with all USB-C chargers. Take a look at PCWorld’s post written three years ago to see someone’s compatibility test; the key example here is that HP’s Spectre X2 will only charge from its own charger. However, take a look at their sequel. and you can see that USB-C has since become a near-universal standard.

Voltaic’s New V88 Portable Laptop Battery with USB-C Power Delivery

For Voltaic Systems’ new battery pack, the V88, the max input and output rate is 20V/2.2A, or 44W. This means that from a USB-PD enabled charger such as the new MacBook Pro AC charging block, the V88 will charge at a 44W rate. This also means that it can charge a new MacBook Pro at 44W, through the same port – but not only a MacBook Pro, almost any device with a USB-PD supported connection! This allows the V88 extreme flexibility in its supported devices, as well as a faster charging rate.

You’ll no longer have to drag around AC bricks for two devices and multiple cables and adapters – all you’ll need is a high quality USB-C cable and one wall adapter to maximize your use of the V88.

For smartphones with USB-PD, it’ll be the same rate it charges from its included wall adapter.

V88 USB-C Power Delivery Charging Table

Take a look below at some of the estimated laptop charge times you’ll be getting using the V88 with USB-PD:

Have a question about your specific USB Type-C device? Contact our Technical Support Team at

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