Compare USB4 and Thunderbolt Ports
USB4 and Thunderbolt are the two high-bandwidth connector families that share the USB-C port, powering data transfer, display output, and fast charging on modern laptops and handhelds. This page compares the specifications of USB4 (v1.0), USB4 v2.0, Thunderbolt 3, Thunderbolt 4, and Thunderbolt 5 side by side, with a chart showing the maximum bandwidth of each port.
Full Specs Comparison
| Specification | USB4 v1.0 | USB4 v2.0 | Thunderbolt 3 | Thunderbolt 4 | Thunderbolt 5 |
|---|---|---|---|---|---|
| 📋 Overview | |||||
| Developer | USB Promoter Group (USB-IF) | USB Promoter Group (USB-IF) | Intel | Intel | Intel |
| Announced | 2019 | 2022 | 2015 | 2020 | 2023 |
| Connector | USB Type-C | ||||
| Built on | Thunderbolt 3 protocol | USB4 v1 architecture | Thunderbolt 2 (mini-DP) | Thunderbolt 3 | USB4 v2 + DisplayPort 2.1 + PCIe Gen 4 |
| ⚡ Bandwidth & Performance | |||||
| Maximum bandwidth | 40 Gbps | 80 Gbps (up to 120 Gbps asymmetric) | 40 Gbps | 40 Gbps | 80 Gbps (up to 120 Gbps with Bandwidth Boost) |
| Mandatory bandwidth | 20 Gbps | 80 Gbps | 40 Gbps | 40 Gbps (always) | 80 Gbps |
| PCIe tunneling | PCIe 3.0 | PCIe tunneling, SuperSpeed USB over 20 Gbps | PCIe 3.0 x4 (22-32 Gbps data) | PCIe 3.0 x4 (32 Gbps, up to ~3,000 MB/s storage) | PCIe 4.0 x4 (64 Gbps) |
| Best for eGPU | Thunderbolt 3-level | Good (PCIe 3.0) | Good (PCIe 3.0) | Good (PCIe 3.0) | Excellent (PCIe 4.0) |
| 🖥️ Display Support | |||||
| DisplayPort | DP over USB4 | DisplayPort 2.1 | DisplayPort 1.2 | DisplayPort 1.4 | DisplayPort 2.1 |
| External displays | Multiple USB-C display | Multiple, higher resolution | 2x 4K @ 60Hz or 1x 5K | 2x 4K @ 60Hz or 1x 8K | 3x 4K @ 144Hz, 2x 6K @ 60Hz, or 1x 8K @ 120Hz |
| 🔌 Power & Compatibility | |||||
| Power delivery | USB PD up to 240W (PD 3.1) | USB PD 3.1 up to 240W | Up to 100W | Up to 100W | USB PD 3.1 up to 240W |
| Backward compatible | USB 3.2, USB 2.0, Thunderbolt 3 | USB4 v1, USB 3.2, Thunderbolt 3/4 | USB 3.1, DisplayPort | Thunderbolt 3, USB4, USB 3.2 | Thunderbolt 3/4, USB4 v1/v2 |
| Required cable length | Standard USB-C | USB-C 80 Gbps | 2 m (passive) | 2 m at full 40 Gbps | Certified USB-C 80 Gbps |
| DMA security (VT-d) | Optional | Optional | Not required | Required | Required |
Best-in-class values highlighted in blue. Specs based on announcements from the USB Promoter Group and Intel.
Quick Takeaways
🏆 Fastest Port
Thunderbolt 5: 80 Gbps symmetric, 120 Gbps with Bandwidth Boost, PCIe 4.0 x4 (64 Gbps) and DisplayPort 2.1 are the best specs of any port here.
🔌 Best Open Standard
USB4 v2.0: matches TB5 bandwidth at 80 Gbps without Intel certification, open to all vendors, with PD 3.1 up to 240W.
🛡️ Safest Modern Pick
Thunderbolt 4: mandates 40 Gbps, PCIe 32 Gbps, 1x 8K support, and VT-d DMA protection; the most common secure port on current laptops.
A short read of the numbers
Bandwidth is the headline difference. USB4 v1.0, Thunderbolt 3, and Thunderbolt 4 all cap at 40 Gbps symmetric, while USB4 v2.0 and Thunderbolt 5 jump to 80 Gbps and can push 120 Gbps in asymmetric mode for display-heavy workloads. Behind that top number, the two newest standards diverge on PCIe: Thunderbolt 5 leaps to PCIe 4.0 x4 (64 Gbps, roughly double the previous generation), which is what makes it the superior choice for external GPUs and high-speed SSDs.
The practical difference is compatibility and security, not just speed. USB4 v2.0 is open and matches TB5 bandwidth without Intel's brand lock-in, while Thunderbolt 4 adds mandatory DMA protection (VT-d), making it the trusted secure default on current premium laptops. For 40 Gbps class ports, Thunderbolt 4 is the refined, mandatory-40 Gbps upgrade over Thunderbolt 3; for the fastest possible eGPU, check whether both the machine and the dock support Thunderbolt 5.
Note: USB4 and Thunderbolt Ports Explained
What these standards are
USB4 and Thunderbolt are standards for high-bandwidth connectivity that run over the USB-C connector. USB4 is defined by the USB Promoter Group (USB-IF) and is open to any vendor. Thunderbolt is engineered by Intel and, while built on the same USB-C physical layer, adds its own certification, mandatory feature set, and brand. Since USB4 v1.0 is based on the Thunderbolt 3 protocol, the two families share deep underlying technology even though they are sold as separate standards.
- All five ports here use the USB Type-C connector, but not every USB-C port supports these speeds.
- Thunderbolt 3 closed the gap between display, data, and power on a single cable back in 2015.
- USB4 adopted the Thunderbolt 3 protocol to bring 40 Gbps speeds to open, vendor-neutral devices.
What bandwidth actually means
Bandwidth is the total data throughput a port can move, measured in gigabits per second (Gbps). A 40 Gbps port transfers roughly 5 GB per second, and 80 Gbps roughly doubles that. In practice, a portion of that bandwidth is consumed by tunneling video (DisplayPort) and carrying PCIe data, so real-world drive throughput is lower than the raw port number; for example, Thunderbolt 4 advertises up to about 3,000 MB/s for storage over its 32 Gbps PCIe allocation.
- Asymmetric or Bandwidth Boost mode reallocates bandwidth one-way, reaching 120 Gbps for heavy display output.
- PCIe tunneling is what lets a port carry an external GPU or an NVMe SSD.
- Cable quality matters: a certified 80 Gbps cable is required to actually hit USB4 v2.0 or TB5 speeds.
Generation by generation
Thunderbolt 3 (2015) brought 40 Gbps and 100W power to USB-C. Thunderbolt 4 (2020) kept 40 Gbps but made it mandatory, doubled minimum video/PCIe requirements, and added mandatory VT-d DMA protection for security. USB4 v1.0 (2019) opened 40 Gbps to USB-IF devices. USB4 v2.0 (2022) and Thunderbolt 5 (2023) both doubled bandwidth to 80 Gbps and added DisplayPort 2.1, with TB5 adding PCIe 4.0 for the biggest eGPU uplift.
- Thunderbolt 4 is not faster than Thunderbolt 3 in peak bandwidth; it is stricter and more secure.
- The real generational jump is 3 to 5, not 3 to 4: TB5 doubles bandwidth and PCIe.
- USB4 v2.0 and TB5 are both 80 Gbps, so the main difference is PCIe speed and Intel certification.
Power and charging
These ports double as power ports via USB Power Delivery. Thunderbolt 3 and 4 deliver up to 100W, enough to charge a laptop. USB4 v1/v2 and Thunderbolt 5 support USB PD 3.1 up to 240W, enabling high-power charging for larger machines and faster device charging through a single cable.
- Higher Power Delivery means a single cable can charge a high-end laptop.
- PD 3.1 extended the ceiling from 100W to 240W.
- Check the wattage rating of the cable, not just the port, for fast charging.
How to choose
For a general laptop, Thunderbolt 4 or USB4 (40 Gbps) is plenty and widely supported. For display-heavy setups, 120 Gbps asymmetric on TB5 or USB4 v2.0 helps. For external GPUs and fastest external storage, Thunderbolt 5's PCIe 4.0 is the clear pick, provided both your machine and dock support it.
- Match the port to the device: an eGPU needs the PCIe throughput of TB5.
- USB4 v2.0 is the open alternative when you want TB5-class bandwidth without Intel branding.
- Always use a certified cable rated for the speed you want to reach.
