USB4 Logo Meaning: What It Really Tells You

The USB4 logo on a cable or port means the device meets the USB4 specification, which guarantees a minimum data transfer speed of 20 Gbps (or 40 Gbps on the full implementation) and is based on the Thunderbolt 3 protocol. In practice, the logo tells you the product has passed certification for USB4’s baseline features, but it does not tell you the exact speed, power delivery wattage, or video capabilities—those are indicated by separate logos and specifications.

Formula

The calculator above works out your average running pace and speed from a finish time and distance. The formulas are:

Pace (min/km) = Finish time (minutes) ÷ Distance (km)

Speed (km/h) = Distance (km) ÷ (Finish time (minutes) ÷ 60)

Where finish time is in minutes, distance is in kilometers, pace is in minutes per kilometer, and speed is in kilometers per hour.

Worked Example

Using the default values: finish time = 50 minutes, distance = 10 km.

• Pace = 50 ÷ 10 = 5.00 min/km
• Speed = 10 ÷ (50 ÷ 60) = 10 ÷ 0.8333 = 12.00 km/h

The calculator shows 5.00 min/km and 12.00 km/h.

Why the USB4 Logo Exists

The USB Implementers Forum (USB-IF) introduced the USB4 logo in 2019 alongside the USB4 specification. The goal was to simplify a confusing landscape of USB 3.x variants, each with different speeds and capabilities. Before USB4, you had USB 3.0 (5 Gbps), USB 3.1 (10 Gbps), and USB 3.2 (20 Gbps), with names that changed retroactively. The USB4 logo is a single mark that indicates the product has passed compliance testing for the USB4 baseline. It does not replace the older logos but sits alongside them.

What the Logo Does NOT Tell You

The USB4 logo alone does not indicate:

• Exact speed: USB4 has two main speeds: 20 Gbps (USB4 20) and 40 Gbps (USB4 40). The base logo does not specify which one you get.
• Power delivery: USB4 supports up to 240W with USB Power Delivery 3.1, but the logo does not state the wattage. Look for a separate Power Delivery logo or the wattage printed on the plug.
• Video bandwidth: USB4 can carry DisplayPort signals, but the logo does not tell you the maximum resolution or refresh rate supported.
• Cable length and quality: A USB4 cable can be passive (up to 0.8 m for 40 Gbps) or active (longer), but the logo does not indicate which type you have.

To know the speed, you need to look for the text “USB4 20� or “USB4 40� printed near the logo, or check the product specification sheet.

How USB4 Relates to Thunderbolt 3 and 4

USB4 is built on Intel’s Thunderbolt 3 protocol, which Intel contributed to the USB-IF. This means a USB4 port can accept a Thunderbolt 3 device, and a Thunderbolt 3 port can accept a USB4 device, provided the hardware supports it. However, Thunderbolt 4 is a separate certification with stricter requirements: it mandates 40 Gbps speeds, PCIe data at 32 Gbps, and dual 4K display support. USB4 does not require those features, so a USB4 device may not match Thunderbolt 4 performance. The USB4 logo does not guarantee Thunderbolt compatibility—only that the port uses the same underlying protocol.

How to Choose a USB4 Cable or Device

When shopping for USB4 products, follow these steps:

1. Check for the USB4 logo on the product or packaging. If it is absent, the device may still be USB4-compatible but not certified.
2. Look for the speed rating (20 or 40) next to the logo. If you need fast external storage or dual 4K monitors, pick 40 Gbps.
3. Verify the power delivery wattage if you plan to charge a laptop. Look for a wattage number (e.g., 60W, 100W) on the charger or cable.
4. Confirm the cable length. For 40 Gbps, a passive cable is typically limited to 0.8 meters; longer cables need active electronics.
5. Check if the device supports DisplayPort Alt Mode if you need video output.

Common Misconceptions

One common mistake is assuming that any USB-C port supports USB4. USB4 requires a USB-C connector, but not all USB-C ports are USB4—many are USB 2.0 or USB 3.x. Another misconception is that the USB4 logo guarantees Thunderbolt 3 support. While the protocols are compatible, the logo does not certify Thunderbolt interoperability. Also, a USB4 cable may not charge your device at the same speed as a dedicated power cable; the logo only covers data and basic power, not the specific wattage.

Frequently Asked Questions

Is USB4 the same as Thunderbolt 4?
No. USB4 is a broader standard with optional features; Thunderbolt 4 is a stricter certification that mandates 40 Gbps, PCIe 32 Gbps, and dual 4K display support. A USB4 device may not meet Thunderbolt 4 requirements.

Can I use a USB4 cable with a Thunderbolt 3 port?
Yes, in most cases. USB4 and Thunderbolt 3 share the same protocol, so they are interoperable, but the actual speed will be limited by the slower port or cable.

Does the USB4 logo mean the cable supports 40 Gbps?
Not necessarily. The logo only indicates USB4 compliance. The speed is usually printed separately as “USB4 20� or “USB4 40�.

Will a USB4 cable charge my laptop?
It can, but the logo does not guarantee a specific wattage. Check the cable’s power delivery rating (e.g., 60W or 100W) to ensure it meets your laptop’s needs.

Do I need a USB4 cable for an external SSD?
For maximum speed, yes, if your SSD supports USB4. But an SSD that runs at 10 Gbps will work fine on a USB4 port, just at its own speed.

Are all USB4 ports the same?
No. USB4 ports can have different speed ratings (20 or 40 Gbps) and different power delivery capabilities. Check the device’s specifications.

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in t | Finish time | min | 50 | 0
in d | Distance | km | 10 | 0 | 100000
out pace | Average pace | min/km | t / d | 2
out speed | Average speed | km/h | d / (t / 60) | 2