Connector shapes
The connector is a physical shape, not a data-speed or power guarantee. USB-C on a device may support only USB 2.0 and no video output.
Schematic front views of cable plugs, not to a common scale. USB-B shows the USB 2.0 shape.
USB-A colors and typical data speeds
Color does not guarantee data speed, power or specification. USB-IF recommends blue for USB 3.0, but does not require it. White, black, teal, red, yellow and orange conventions vary by manufacturer. Prefer SS/5/10 markings and product specifications.
Data transfer standards
Rates are nominal link rates, not file-transfer speeds. Device, cable, protocol overhead and storage performance affect the actual result. USB version names do not determine cable power.
20Gbps can mean USB 3.2 Gen 2×2 or USB4. Confirm the same protocol at both ends; the number alone is insufficient.
*1 USB4 Version 2.0 optionally supports asymmetric operation at 120Gbps in one direction and 40Gbps in the other. Compatible equipment is required; this is not a separate 120Gbps cable speed class.
Power and charging
A cable’s power rating is the maximum power it can carry and is independent of data speed. Power = voltage × current. Actual charging depends on compatible charger, cable and device profiles; a higher-rated cable alone does not increase charging power.
Current USB-IF C-to-C cable certification uses 60W or 240W power markings, separately or combined with speed. Existing 100W cables remain relevant, but are not EPR cables.
How to read cable specifications
Check data speed and cable power rating separately. These are examples of product markings, not a claim that every cable supports every combination.
- 480Mbps + 240W: high-power charging, USB 2.0 data; no automatic video capability.
- 10Gbps + 60W: fast data, with a maximum cable power rating of 60W.
- 10Gbps + 240W: fast data and high-power charging; verify video support separately.
Choosing a cable by use
Start with the device specifications, then look for explicit connector, data-speed, power and video ratings in the cable description. The numbers below illustrate how to choose; they are not universal requirements for each use.
VR headset
Check the headset’s specified connection, data rate and cable length. USB video streaming and headsets using separate DisplayPort or HDMI connections need different cables. For charging while playing, check the PC port or a compatible powered link cable as well.
Example:For a headset requiring USB 3.0 at 5Gbps or higher, choose a data cable rated at least 5Gbps with the correct connectors and length. For a 3 m cable, check that the actual 3 m model explicitly supports the required speed and headset.
Pen display with one cable
Confirm that the pen display supports a single USB-C connection and the PC port provides DisplayPort Alt Mode video and USB data. Choose a full-featured USB-C cable with video support, and check whether the PC port can supply enough power to run the display.
Example:If the display needs 15W, the PC port must supply 15W at the required voltage and current. A cable marked “video support / 60W” cannot make up for insufficient PC power; a separate supply may still be needed. Check the manufacturer’s recommended cable and the intended resolution and refresh rate.
Fast charging
Match the device’s charging protocol and required power with the charger and cable. USB PD, PPS and proprietary charging have different requirements; “fast charging” alone is not a sufficient specification.
Example:For 100W USB PD charging, choose a 5A USB-C cable. Legacy “100W / 5A” and current “240W / 5A” markings both meet the cable requirement for PD charging up to 100W. Above 100W requires a 240W EPR cable. A phone advertising proprietary 100W charging may need the manufacturer’s specified charger and cable.
USB storage
Match the PC and storage connectors, speed and protocol. USB 3.2 Gen 2×2, USB4 and Thunderbolt are distinct modes; the same Gbps number does not establish compatibility.
Example:For a 10Gbps USB SSD, choose a data cable rated at least 10Gbps with matching connectors, and check that the PC port supports 10Gbps. A 5Gbps cable limits the link speed. A 20Gbps Gen 2×2 SSD also needs Gen 2×2 support in the PC and cable.
USB-C monitor
Check video support on the PC and monitor USB-C ports, plus cable support for the intended resolution and refresh rate. If the monitor charges the PC, check its power output and the cable power rating too.
Example:For 4K at 60Hz while supplying 65W to a laptop, look for explicit “4K 60Hz video” and “5A power (legacy 100W or current 240W marking)” support. Since 65W exceeds 60W, a 60W cable is insufficient. The PC and monitor must also support the display mode and 65W PD charging.
Dock or hub
Match the dock’s upstream connection to the PC: USB 3.x, USB4 or Thunderbolt. Check display, storage and laptop charging requirements. The dock’s output to the PC may be lower than its charger input.
Example:For a dock requiring Thunderbolt 4, choose a compatible Thunderbolt 4 certified cable. For 90W laptop charging, check an explicit cable power rating of at least 100W and at least 90W output from the dock to the PC. The Thunderbolt 4 name alone does not establish 240W EPR support.
Ratings apply to the actual cable length. Different lengths in the same product family may have different data or video capabilities, so check the exact model you will buy.
Notes and terminology
Gbps means gigabits per second; GB/s means gigabytes per second. With 8 bits per byte, 10Gbps is theoretically 1.25GB/s, but protocol overhead and device performance reduce actual file-transfer speeds. Charge-only cables may not carry data. Hubs, adapters and active cables have additional limits. A Thunderbolt lightning logo or DisplayPort DP logo is a clue; confirm capabilities in the device specifications.
Terms used on this page
- Nominal link rate
- The specification’s communication link speed. Cable data-speed markings such as 5Gbps or 10Gbps indicate supported link rates, not measured file-transfer speeds.
- Cable power rating and power output
- Cable power rating is the maximum power the cable can carry. Power output is what a charger, monitor or dock can supply to a device. Both must meet the intended charging requirements.
- SuperSpeed
- An older USB 3.x data-transfer name. SuperSpeed USB means 5Gbps; SuperSpeed USB 10Gbps means 10Gbps. Products may now be marked directly with speeds such as 5Gbps and 10Gbps.
- e-marker
- An electronic component in the cable that reports capabilities such as current rating and data features to connected equipment. A 5A cable needs one, but an e-marker alone does not establish 5A or video support.
- SPR / EPR
- USB PD power ranges: Standard Power Range (SPR) supports up to 100W; Extended Power Range (EPR) supports up to 240W. Above 100W needs EPR support in the source, device and cable.
- PPS
- Programmable Power Supply: a USB PD feature for fine voltage and current adjustment. Some fast-charging modes require PPS support in both the charger and device.
- Alt Mode (Alternate Mode)
- Uses USB-C high-speed wiring for signals other than USB data. DisplayPort Alt Mode carries video this way. A USB-C connector shape alone does not establish support.
- Full-featured USB-C cable
- A USB-C cable with high-speed data / Alt Mode wiring as well as USB 2.0 wiring. Here this means a USB-C to USB-C cable. Unlike a USB 2.0-only cable, it has the extra wiring, but the term does not guarantee every resolution, refresh rate or power level. Check explicit video support and power rating.
Official sources
Sources checked: 2026-10-01
