Data Cable Speed and Wattage

Not all cables are the same; USB-C cables vary wildly and can carry anywhere from 60W to 240W of power, and 480 Mbps to 40 Gbps of data. Just because a cable has the same connector shape doesn’t mean it supports high-speed transfers or fast charging.

Cable Speed and Wattage Standards

• USB 2.0 (Entry-Level):

  • Data Speed: Up to 480 Mbps (roughly 60 MB/s).

  • Wattage: Often limited to 60W (20V × 3A), but older USB-A to C versions max out around 15W (5V × 3A).

• USB 3.2 Gen 1 (formerly USB 3.0):

  • Data Speed: Up to 5 Gbps.

  • Wattage: Delivers up to 15W (5V × 3A) standard, but some cables support up to 60W.

• USB 3.2 Gen 2 / Gen 2x2:

  • Data Speed: 10 Gbps to 20 Gbps.

  • Wattage: 60W (20V × 3A) to 100W (20V × 5A).

• USB4 / Thunderbolt 3 & 4 (Top Tier):

  • Data Speed: Up to 40 Gbps.

  • Wattage: Supports up to 240W via Extended Power Range (EPR).

Key Things to Know

• The Connector Isn't the Cable: The "USB-C" name only dictates the shape of the plug. The internal wiring determines exactly how fast it transmits data or charges a device.

• E-Markers: High-wattage (above 60W) and high-speed USB-C cables require a built-in microchip (E-marker) to safely communicate capabilities to connected devices.

• USB-A vs. USB-C: Cables ending in the older, rectangular USB-A generally cap out at 7.5W to 18W, and typically stick to USB 2.0 or 3.0 data speeds.