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Quick answer
Thunderbolt 4, USB4, and standard USB-C cables all use the exact same reversible USB Type-C connector, so any of them will physically slide into your laptop or monitor. The difference is what the certification requires to be wired inside. A basic USB-C charge cable only has to carry 480 Mbps data and 60W power with zero video lanes. A USB4 cable can be either 20 Gbps or 40 Gbps. A certified Thunderbolt 4 cable mandates the ceiling of every spec at once: 40 Gbps bandwidth, DisplayPort video for two 4K 60Hz monitors (or one 8K display), PCIe tunneling, and 100W to 240W Power Delivery.
Universal Thunderbolt 4 / USB4 cables: one cable that works at the maximum speed of any USB-C, USB4, Thunderbolt 3, or Thunderbolt 4 port.
Plugable TB4 240W (1m) CalDigit TB4 / USB4 Cable Belkin Thunderbolt & USB-C StarTech Certified CablesSide-by-side spec comparison: USB-C vs USB 3.2 vs USB4 vs Thunderbolt 4
| Cable type | Data speed | Video support (DisplayPort) | Power Delivery | PCIe data tunneling |
|---|---|---|---|---|
| USB-C 2.0 (Charge cable) | 480 Mbps | None (no SuperSpeed lanes wired) | 60W (3A) or 100W/240W (5A E-Marked) | No |
| USB-C 3.2 Gen 2 (Full-feature) | 10 Gbps (or 20 Gbps Gen 2×2) | Yes — DP Alt Mode (typically single 4K 60Hz) | 60W, 100W, or 240W | No |
| USB4 (Gen 2 / Gen 3) | 20 Gbps or 40 Gbps (up to 80 Gbps in USB4 v2) | Yes — mandatory support for at least one display | 60W to 240W (100W+ with 5A E-Marker) | Optional on USB4 hosts; supported in 40 Gbps cables |
| Thunderbolt 3 | 40 Gbps (passive ≤0.8 m) or 20 Gbps (passive 1–2 m) | Yes — up to two 4K 60Hz or one 5K 60Hz display | 60W or 100W | Yes (minimum 16 Gbps) |
| Thunderbolt 4 | Always 40 Gbps (up to 2 m universal) | Yes — mandatory two 4K 60Hz or one 8K display (DP 1.4 HBR3) | 100W minimum (up to 240W EPR on newer cables) | Yes (mandatory 32 Gbps on TB4 hosts) |
Why Thunderbolt 4 is the "one cable that works everywhere"
As Plugable's Thunderbolt 3 vs. Thunderbolt 4 vs. USB4 engineering breakdown and CalDigit's Thunderbolt 4 cable documentation explain, Thunderbolt 4 was designed on top of the USB-IF USB4 architecture to eliminate the guesswork that plagued early USB-C and Thunderbolt 3 cords:
- No 20 Gbps speed drop on 1-meter to 2-meter cables: with older passive Thunderbolt 3 cables longer than 0.8 m (2.6 ft), speed dropped in half from 40 Gbps to 20 Gbps, and active 40 Gbps Thunderbolt 3 cables lost backward compatibility with standard USB 3.2 devices. Thunderbolt 4 universal cables support the full 40 Gbps across Thunderbolt, USB4, and USB 3.2 at lengths up to 2 meters (6.6 ft).
- Guaranteed backward compatibility: a Thunderbolt 4 cable plugs into any USB-C, USB 3.2, USB4, Thunderbolt 3, or Thunderbolt 4 port and automatically negotiates the highest speed and video mode that the host and device share.
- 100W minimum power (240W on EPR versions): every certified Thunderbolt 4 cable is E-Marked for at least 100W (20V/5A), and newer Release 2.1 Extended Power Range models — such as the Plugable
TBT4-240W-1Mand CalDigit Thunderbolt 4 / USB4 Cable — support up to 240W (48V/5A).
Why MacBooks and Windows laptops behave differently on dual-monitor docks
One of the most common home-office headaches happens when a dual-monitor USB-C dock drives two extended screens from a Windows work laptop, but mirrors the same image on both monitors when plugged into a MacBook:
- Windows supports DisplayPort MST (Multi-Stream Transport): a Windows laptop with a standard USB-C DisplayPort Alt Mode port can split a single DisplayPort video stream into two independent monitors through a standard USB-C MST hub.
- macOS does not support DisplayPort MST for dual extended monitors: as Plugable and CalDigit dock guides document, macOS only drives two independent extended displays over a single cable when both the dock and the cable use native Thunderbolt 3 / Thunderbolt 4 (which tunnels two separate DisplayPort streams) — and the Mac's Apple silicon chip supports two external displays.
- Check your Mac's chip limit first: per Apple Support (article 101571), MacBooks with Pro or Max chips (M1/M2/M3/M4 Pro and Max), plus M3 MacBook Air/Pro (with the laptop lid closed) and M4 MacBook Pro, support two or more external displays over Thunderbolt. Base M1 and M2 MacBook Air and 13-inch MacBook Pro models natively support only one external display over Thunderbolt without DisplayLink software.
How we work: all bandwidth minimums, cable length rules, and host requirements on this page come from USB-IF's USB4 specification, Apple Support articles 118204 and 101571, Plugable, and CalDigit documentation, linked below.
Questions people ask
Does a Thunderbolt 4 cable work in a regular USB-C or USB4 port?
Yes. Certified Thunderbolt 4 cables are backward-compatible with USB4, Thunderbolt 3, and standard USB-C (USB 3.2 and USB 2.0) ports. When plugged into a non-Thunderbolt USB-C port, the cable automatically operates at the highest data speed, DisplayPort Alt Mode video, and Power Delivery wattage that the port supports.
What is the difference between a Thunderbolt 4 cable and a USB4 cable?
Thunderbolt 4 mandates the top tier of every spec: 40 Gbps bandwidth, support for two 4K 60Hz displays (or one 8K display), PCIe tunneling, at least 100W Power Delivery (up to 240W EPR), and full 40 Gbps performance up to 2 meters. USB4 cables can be certified at either 20 Gbps or 40 Gbps and only mandate support for a single display.
Why does my dual-monitor USB-C dock show the same screen on both monitors on my MacBook?
macOS does not support DisplayPort Multi-Stream Transport (MST) daisy-chaining over standard USB-C, so a non-Thunderbolt USB-C dock mirrors both screens on a Mac. Driving two extended displays over one cable on macOS requires a native Thunderbolt 3 or Thunderbolt 4 dock and cable, plus a Mac chip that supports two external monitors (such as M1/M2/M3/M4 Pro or Max, M4, or M3 with the laptop lid closed).
Sources
Last checked Oct 23, 2026. USB-C port features vary by laptop and monitor model; check your computer and display tech specs before buying.
- USB-IF: USB4 Specification
- USB-IF: USB Type-C Cable and Connector Specification
- Plugable: What's the Difference Between Thunderbolt 3, Thunderbolt 4, and USB4
- Plugable: Thunderbolt 4 240W EPR Cable (1m)
- CalDigit: Thunderbolt 4 / USB4 Cable (0.8m, 1m, 2m)
- Apple Support: About the Apple Thunderbolt Pro Cables
- Apple Support: How many displays can be connected to MacBook Pro
