The cable matrix
Every USB-C cable is one of these 14 classes. The class decides what can pass; the label on the box often does not say which class you are buying. Data rate, wattage, and video capability are independent axes, which is the whole confusion.
Cable classes — maximum ratingsper USB-IF and Intel cable specifications
| Class | Data | Video | Power | e-marker | TB cert | Notes |
|---|---|---|---|---|---|---|
| USB 2.0 charging cable (3 A, 60 W) | 480 Mbps | no | 60 W | no | none | The default drawer cable. Charges at up to 60 W and syncs at USB 2.0 speed. No SuperSpeed pairs are wired, so it can never carry video, regardless of what the devices support. |
| USB 2.0 charging cable (5 A e-marked, 100 W) | 480 Mbps | no | 100 W | yes | none | Pre-EPR 100 W charging cable, common with older high-power laptop chargers. USB 2.0 data only, no video. |
| USB 2.0 EPR charging cable (5 A, 240 W) | 480 Mbps | no | 240 W | yes | none | Modern 240 W-rated charging cable (USB PD 3.1 EPR). Still USB 2.0 data only, still no video. Wattage rating and data capability are independent axes. |
| Full-featured USB-C, 5 Gbps (3 A, 60 W) | 5 Gbps | yes | 60 W | no | none | The cheapest cable that can carry video. All four SuperSpeed lanes wired, so DP alt mode works up to the port's own limit. |
| Full-featured USB-C, 5 Gbps (5 A, 100 W) | 5 Gbps | yes | 100 W | yes | none | Video plus 100 W charging in one cable. 240 W-rated full-featured cables exist but are typically sold as USB4 cables; see the USB4 and TB4 classes. |
| Full-featured USB-C, 10 Gbps (3 A, 60 W) | 10 Gbps | yes | 60 W | no | none | 10 Gbps data and DP alt mode, light-duty charging. |
| Full-featured USB-C, 10 Gbps (5 A, 100 W) | 10 Gbps | yes | 100 W | yes | none | The common good all-rounder before USB4: 10 Gbps, video, 100 W. |
| Full-featured USB-C, 20 Gbps (5 A, 100 W) | 20 Gbps | yes | 100 W | yes | none | USB 3.2 Gen 2x2. Rare in the wild; 20 Gbps only works between two Gen 2x2 ports, which are themselves rare. |
| USB4 cable, 20 Gbps (5 A, 240 W) | 20 Gbps | yes | 240 W | yes | none | USB4 Gen 2x2. Retail USB4 cables are commonly 240 W-rated; 60 W variants exist, check the packaging. |
| USB4 cable, 40 Gbps passive (5 A, 240 W, ≤ 0.8 m) | 40 Gbps | yes | 240 W | yes | none | Passive 40 Gbps tops out around 0.8 m. Longer passive cables silently drop to 20 Gbps. Also works as a Thunderbolt 3 passive cable in practice. |
| Thunderbolt 3 active cable, 40 Gbps (5 A, 100 W) | 40 Gbps | no | 100 W | yes | TB3 | The legacy trap cable. 40 Gbps between two Thunderbolt 3 devices, but its active retimers do not pass DP alt mode, and USB data falls back to USB 2.0 on non-Thunderbolt hosts. Looks identical to a universal cable. |
| Thunderbolt 4 universal cable, 40 Gbps (5 A, 100 W) | 40 Gbps | yes | 100 W | yes | TB4 | Does everything at full speed with every port type, up to 2 m. The safe default answer when in doubt. |
| Thunderbolt 4 universal cable, 40 Gbps (5 A, 240 W) | 40 Gbps | yes | 240 W | yes | TB4 | Thunderbolt 4 universal behavior plus 240 W EPR charging. |
| USB4 v2 / Thunderbolt 5 cable, 80 Gbps (5 A, 240 W) | 80 Gbps | yes | 240 W | yes | TB5 | USB4 Gen 4. 80 Gbps symmetric, 120/40 Gbps asymmetric for display bandwidth on Thunderbolt 5 links. |
The three rules that resolve most arguments
- Wattage and data are independent. A 240 W cable can be a USB 2.0 cable. Most are.
- Video needs the SuperSpeed pairs. If a cable is a charging cable, no port on earth pushes video through it.
- Above 60 W needs an e-marker; above 100 W needs EPR. Without them the link quietly negotiates down, and nothing tells you.
Every class row above carries its specification citation in the corpus, and each verdict on the bench repeats the ones it used.