Quick Answer
USB maximum data rates climb from 480 Mbps (USB 2.0) to 5 Gbps (USB 3.2 Gen 1), 10 Gbps (USB 3.2 Gen 2), 20 Gbps (USB 3.2 Gen 2x2 and USB4 Gen 2x2), 40 Gbps (USB4 Gen 3x2), and 80 Gbps (USB4 Version 2.0, up to 120 Gbps asymmetric). Thunderbolt 3 and Thunderbolt 4 both run at 40 Gbps, while Thunderbolt 5 reaches 80 Gbps bidirectional and up to 120 Gbps with Bandwidth Boost. USB-C is the connector for everything from USB 3.2 Gen 2x2 onward.
USB & Thunderbolt Speed Comparison Table
| Standard | Max Data Rate | Connector | Common Use / Notes | Year |
|---|---|---|---|---|
| USB 2.0 (Hi-Speed) | 480 Mbps | A / B / Micro / USB-C | Keyboards, mice, printers, basic flash drives | 2000 |
| USB 3.2 Gen 1 (was USB 3.0 / 3.1 Gen 1, "SuperSpeed") |
5 Gbps | A / B / USB-C | External HDDs, USB drives, docks, general SuperSpeed | 2008 |
| USB 3.2 Gen 2 (was USB 3.1 Gen 2, "SuperSpeed 10Gbps") |
10 Gbps | A / USB-C | Fast external SSDs, higher-end docks | 2013 |
| USB 3.2 Gen 2x2 ("SuperSpeed 20Gbps") |
20 Gbps | USB-C only | Dual-lane USB-C SSDs (USB-C connector required) | 2017 |
| USB4 Gen 2x2 | 20 Gbps | USB-C only | Entry USB4 tier; tunnels USB, DisplayPort, PCIe | 2019 |
| USB4 Gen 3x2 | 40 Gbps | USB-C only | High-end USB4; matches Thunderbolt 3/4 bandwidth | 2019 |
| USB4 Version 2.0 | 80 Gbps (up to 120 Gbps asymmetric) | USB-C only | Latest USB4; 120 Gbps asymmetric mode drives high-res displays | 2022 |
| Thunderbolt 3 | 40 Gbps | USB-C | eGPUs, docks, dual 4K; Intel protocol that became USB4 | 2015 |
| Thunderbolt 4 | 40 Gbps | USB-C | Stricter minimums than TB3: dual 4K or single 8K, 32 Gbps PCIe, 100W+ charging | 2020 |
| Thunderbolt 5 | 80 Gbps (up to 120 Gbps with Bandwidth Boost) | USB-C | Bidirectional 80 Gbps; 120 Gbps for high-refresh multi-monitor setups; up to 240W | 2023/2024 |
Data rates are theoretical maximums defined by each specification. Real-world throughput is lower due to protocol overhead. Sources: USB Implementers Forum (USB-IF) and Intel Thunderbolt specifications.
Why USB Naming Is So Confusing
The USB-IF has renamed the same standards multiple times, which is why a single 5 Gbps port can be labeled three different ways. Here is the key thing to remember:
USB 3.0 = USB 3.1 Gen 1 = USB 3.2 Gen 1 = 5 Gbps. They are identical in speed, just renamed in 2013 and again in 2017. Likewise, USB 3.1 Gen 2 became USB 3.2 Gen 2 (10 Gbps).
To cut through it, the USB-IF now recommends consumer-facing names based purely on speed: SuperSpeed USB 5Gbps, SuperSpeed USB 10Gbps, SuperSpeed USB 20Gbps, and for USB4, USB 40Gbps and USB 80Gbps. When in doubt, ignore the "Gen" label and look for the Gbps number printed on the port or in the spec sheet.
Power Delivery: Speed Is Not the Whole Story
USB Power Delivery (USB-PD)
- ✓Up to 240W: The Extended Power Range (EPR) profile in USB-PD 3.1 delivers 48V at 5A, enough for many gaming laptops.
- ✓Independent of data speed: A USB 2.0 cable can still carry high power, and a fast data cable may not support full EPR. Check the cable rating.
- ✓Single-cable setups: Charge a laptop, drive a display, and move data over one USB-C connection.
Thunderbolt Power
- ✓100W minimum (TB4): Thunderbolt 4 requires at least 100W charging on at least one port.
- ✓Up to 240W (TB5): Thunderbolt 5 raises the ceiling to 240W, aligning with USB-PD EPR.
- ✓Guaranteed PCIe data: 32 Gbps of PCIe tunneling for external SSDs and GPUs, a key TB4/TB5 advantage over plain USB4.
Which Standard Do You Actually Need?
Keyboards, mice, webcams, printers
USB 2.0 (480 Mbps) is plenty. These low-bandwidth peripherals gain nothing from a faster port.
External hard drives and basic SSDs
USB 3.2 Gen 1 (5 Gbps) saturates any spinning hard drive. For a mainstream SATA SSD, USB 3.2 Gen 2 (10 Gbps) is the sweet spot.
Fast NVMe external SSDs
USB 3.2 Gen 2x2 (20 Gbps) or USB4 / Thunderbolt (40 Gbps) to unlock the full speed of a modern portable NVMe drive.
Docks, eGPUs, multi-monitor, 8K displays
Thunderbolt 4 / USB4 (40 Gbps) for guaranteed display and PCIe support, or Thunderbolt 5 / USB4 Version 2.0 (80-120 Gbps) for the most demanding high-refresh, multi-display, and external-GPU workflows.
Frequently Asked Questions
USB4 Version 2.0 is the fastest USB standard, with a symmetric data rate of 80 Gbps and up to 120 Gbps in an asymmetric mode used for driving high-resolution displays. It matches Thunderbolt 5, which also runs at 80 Gbps bidirectional and up to 120 Gbps with Bandwidth Boost.
They are all the same 5 Gbps standard under different names. The USB Implementers Forum (USB-IF) renamed the original USB 3.0 to USB 3.1 Gen 1 in 2013, then to USB 3.2 Gen 1 in 2017. All three deliver an identical 5 Gbps maximum data rate. The current official marketing name is SuperSpeed USB 5Gbps.
They are closely related but not identical. Both can run at 40 Gbps over a USB-C connector, and USB4 is built on the Thunderbolt 3 protocol that Intel donated to the USB-IF. The difference is that Thunderbolt 4 enforces stricter mandatory minimums: guaranteed 40 Gbps, dual 4K or single 8K display support, 32 Gbps of PCIe data for external GPUs and SSDs, and certification. Many USB4 ports meet only the lower required floor (such as 20 Gbps).
USB 2.0 (Hi-Speed) tops out at 480 Mbps, which is 0.48 Gbps. USB 3.2 Gen 2 (SuperSpeed USB 10Gbps) reaches 10 Gbps, roughly 20 times faster in raw maximum data rate.
USB Power Delivery (USB-PD) supports up to 240W using Extended Power Range (EPR) at 48V and 5A, introduced with the USB-PD 3.1 specification. Thunderbolt 4 and Thunderbolt 5 require at least 100W of charging power on at least one port, with Thunderbolt 5 supporting up to 240W.
Yes. Thunderbolt 5 uses the USB-C connector and is backward compatible with Thunderbolt 4, Thunderbolt 3, USB4, and standard USB devices. A slower device will simply negotiate down to the highest speed both ends support.
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