USB-C chaos, demystified: Know what power and data you’re really getting

You can easily find laptops and desktop PCs packing USB-C port certified for Thunderbolt 4 or USB 4. But now the next generation of the standard is picking up speed with Thunderbolt 5 (TB 5) and USB 4 version 2 (USB 4 v2).

These catapult the data transfer speed from the 40 GBit/s of the previous generation all the way up to 80 GBit/s. And in asymmetric mode, which is optional with USB 4 v2, data transfer is even possible at 120 GBit/s from the host to connected peripheral devices (downstream) to let you run multiple high-resolution monitors at once. (In the opposite direction, 40 GBit/s are still possible.)

Phew! That’s a lot of information. My head is spinning. And that’s why Microsoft is rolling out new requirements to end USB-C chaos on Windows 11 laptops: The state of USB-C and Thunderbolt is absolutely befuddling even for experts.

At least TB 5 and USB 4 v2 remain backwards compatible. This means that you can continue to connect legacy peripherals via adapters — even older devices with USB 2.0 ports. But there are still plenty of practical questions about USB-C, and especially about the current TB 5 and USB 4 v2 versions.

You’ll find answers to the most pressing questions here — for example, how to find out whether your devices are already based on the current standards, what specifications and features to look for when buying, and how to read the new-look USB logos.

Further reading: Tested! These are the best USB-C cables for charging and data transfers

Find out USB 4 information via Windows

If you have a Windows 11 computer with USB-C ports and are not sure whether the Type-C ports support USB 4, you can find out via the Windows settings app. Windows 11 now includes a “USB4 hubs and devices” feature, located under “Bluetooth and devices > USB.” You can also get there by typing “USB4” or “Thunderbolt” into the search bar.

There, you can find out which version of USB 4 is supported by your system. This is because the “USB4 version” line contains precise information. If you see “1.0” there, the USB host controller provides a maximum bandwidth of 40 GBit/s. With “2.0” listed, you already have a system that supports USB 4 version 2 (USB 4 v2) at twice the speed — possibly even with the optional asymmetric mode.

At the same time, Windows 11 also provides information about connected devices at the moment. For example, if you plug an external USB 4 or Thunderbolt 4/5 SSD into the Type-C port and then click on “Refresh” next to “USB4 domain information,” the name of the connected device will appear under “USB4 host router information.”

If you click on this or on the plus sign at the end of the line, you will receive additional information: “Current bandwidth (down/up)” shows what speed is currently possible on your USB-C port with the device. Somewhat confusingly, the information does not have to correspond to the maximum speed that the device can generally handle. The combination of interface and connected device is displayed.

Please note: This Windows 11 feature is only available for USB4-compatible computers. It isn’t available for PCs with USB 2.0 and 3.0 ports.

New USB logos provide an easier overview

The USB Implementers Forum (USB-IF), which is responsible for the standard, adapted the USB labels again at the beginning of 2025 to make it easier to see what a USB-C device or cable supports before you buy it. New logos should show at a glance what speed and performance can be expected from USB Type-C products.

In doing so, the USB-IF wants to counteract the frequently voiced criticism that the endless variations create more confusion than clarity regarding Type-C.

Instead of technical terms, the new logos focus on the connector’s key capabilities. Data transfer speed and charging performance must be immediately recognizable. Ideally, you will see the speed information next to “USB” on the product packaging – for example “80 Gbps.” This lets you know that the device is certified for data transfers of up to 80 GBit per second.

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Under this new scheme, the USB-C connections directly on a device (such as a notebook or desktop PC) should make the maximum transfer rate clear via a written number. The reform of the logos also affects the USB-C cables; the data speed and the power rating must be indicated on the plugs – both clearly recognizable, one below the other.

For example, a USB-C cable labeled “80 Gbps 240 W” means that the cord can transmit data at up to 80 Gbps and charge devices with a maximum of 240 watts.

If you can only charge with a cable, the information on the transfer speed is omitted. That makes it immediately clear that no data can be transferred via the cable in question, or that only very slow transfers at USB 2.0 speed are possible.

The commendable initiative has one drawback: The USB committee leaves it up to the manufacturers to decide whether or not to use the new logos. In any case, you can be sure that a product with the logo is more trustworthy than a device or accessory without the logo.

Further reading: 9 nifty USB-C gadgets you didn’t know you needed

The right cables and power supply units for charging via USB-C

More and more devices are using USB-C plugs for charging. It’s no surprise; a European Union regulation now stipulates that new devices must be able to be charged via USB-C.

There is a transition period for notebooks that ends on April 28, 2026. After this date, proprietary plug/power supply combinations will also be a thing of the past. All notebook batteries must be able to be charged via USB-C.

Although the USB-C connector is used for the power supply, the charging processes are regulated in a separate specification: USB Power Delivery (USB PD).

It provides for different charging profiles (power profiles). In the extended version (USB PD EPR, Extended Power Range), the charging power goes up to 240 watts. This means that even power-hungry gaming notebooks can be supplied with sufficient energy.

Further reading: The bewildering world of USB-C charging, explained

But this requires the charging cable to be able to keep up. To do this, it must be equipped with a special chip called an e-marker, from a current of 5 amps. This stores the capabilities of the cable, such as the charging profiles or the maximum power supply capacity.

If you don’t want to work your way through the PD specifications, you should at least opt for a power supply unit from 45 watts or 60 watts when looking for an all-round power supplier. With this charging power, you can power a compact notebook and charge the majority of smaller devices such as smartphones or tablets.

More powerful mobile computers require a 100 watt power supply unit (20 volts at 5 amps). An overview of PD charging profiles and suitable example devices can be found in the table.

Overview: Charging performance via USB Power Delivery (PD)

Even 5 volts at 48 amps for up to 240 watts via a USB-C cable, which was unattainable until recently, is now possible. One of the first power supply units for this can be found in the Delta ADP-240KB BA.

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You can call up all USB EPR-certified charging profiles. But Delta’s 240W USB-C charging brick is obviously bulky and less than ideal when travelling.

Nevertheless, there is no doubt as to whether its charging cable is designed for the power. It’s firmly attached to the power supply unit! The only thing beefier than this do-it-all USB-C charger is its price: $150.

USB 4 v2 and TB 5 rare so far

If you’re thinking about buying a new computer, you also want to be up to date with the latest external interfaces.

At the moment, the wish is still proving to be a challenge. For example, current notebooks with Intel CPU generation of the Core Ultra 200 series (codename: Arrow Lake H and HX) are labelled “Thunderbolt 5 ready.” This means that the processors are basically prepared for TB 5 — in other words, they support enough PCI Express lanes to provide the bandwidth.

However, they require an additional chip in order to fulfil the TB 5/USB 4 v2 specifications. One possibility is Intel’s controller JHL9580 (codename: Barlow Ridge), but it is up to the PC manufacturers to decide whether to install it. Because of that, we have so far only found a few notebook models with Thunderbolt 5 Type-C interfaces, such as the new Razer Blade 18 and the MSI Vector 16 HX.

These are both powerful gaming laptops with expensive price tags. With prices starting around $3,000, the additional costs for installing the TB5 controller chip do not play such a large role in the overall calculation. This also applies in a similar way to the Apple MacBook series with M4 processors, which also support TB 5.

At the same time, the high requirements of TB 5 and USB 4 v2 in terms of data rates, loading speed, and video signals mean that sufficient cooling must be provided. An additional fan may even have to dissipate the waste heat outside the PC’s case. This is an important point, especially for very slim and lightweight laptops, which has a direct impact on weight and noise.

Because of that, we’re seeing laptop makers continue to make do with the older TB 4/USB 4 standard and maximum data rates of 40 GBit/s for ultra-mobile computers.

Retrofitting USB-C sockets for TB 5/USB 4 v2

In contrast to notebooks, new desktop PCs are more likely to have a USB-C interface that already supports TB 5/USB 4 v2. This means that it can possibly be retrofitted with a PCIe expansion card.

Again, the motherboard must always be qualified as “Thunderbolt 5 ready.” This ensures that the necessary Thunderbolt header is available. At the moment, this is most likely to be the case with high-end PCs, such as systems with Intel Z890 mainboards.

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You also need a free PCIe 4.0 slot with four lanes (x4). If these requirements are met, you can purchase a corresponding PCI-e add-in card, like the $140 Asus Thunderboltex 5.

The JHL9580 “Barlow Ridge” controller chip already mentioned is used here. In addition to the full Thunderbolt 5 data transfer speed, the two TB-5 type C sockets also provide a fast charging up to 130 watts and a power supply of up to 96 watts for a connected device.

There are also three Mini-Displayport 2.1 ports, which you can use to connect up to three monitors with 8K resolution and a refresh rate of 60 hertz.

Further reading: Tested! These are the best USB-C cables for charging and data transfers