If you’re picking a laptop, dock, cable, or eGPU setup, the port label decides how many displays you can run, how fast your storage moves, and whether a single cable can power everything.
Table of Contents
At a glance (spec highlights)
| Feature | TB3 | TB4 | TB5 | USB4 (v1 & v2) |
| Total link bandwidth | 40 Gbps | 40 Gbps | 80 Gbps bi-dir, up to 120 Gbps to displays | 20/40 Gbps (v1), 80 Gbps (v2) |
| PCIe data (tunneled) | Up to 32 Gbps (varies by laptop; many at 16–32) | 32 Gbps guaranteed | 64 Gbps (PCIe Gen 4 x4) | Varies by host; v2 improves data tunneling |
| Display tunneling | DP 1.2/1.4 (varies by controller) | DP 1.4 | DP 2.1 | DP 1.4 (v1) / DP 2.1 (v2) |
| Typical display configs | Up to 2×4K@60 (or 1×5K) | 2×4K@60 (or 1×8K with DSC) | Multiple 8K, or 3×4K@144 (on capable gear) | Similar to TB level matched (depends on version) |
| USB-C power (host charging) | Up to 100 W | Up to 100 W | Up to 240 W (USB PD 3.1 EPR) | Up to 240 W with USB PD 3.1 EPR |
| Connector | USB-C | USB-C | USB-C | USB-C |
| Back-compat | — | Works with TB3 | Works with TB4/TB3 | Interoperable within USB4 family |
What changed by 2025
TB5 is shipping in laptops and next-gen docks. It doubles the baseline link to 80 Gbps and adds a dynamic 120 Gbps “Bandwidth Boost” for display-heavy setups—how you get multi-8K or triple-4K high-refresh from a single USB-C port.
USB4 v2 (80 Gbps) brings the same lane speed and DP 2.1 tunneling to non-Thunderbolt platforms, so some AMD/other systems hit TB5-class display bandwidth without the Thunderbolt badge.
Power finally scales to big laptops via USB PD 3.1 EPR (up to 240 W), enabling true one-cable desks for many gaming/workstation machines.
How each one feels in real use
Thunderbolt 3 (foundation, but inconsistent)
TB3 launched the 40 Gbps era, but implementations varied. Some laptops wired only two PCIe lanes (effectively halving data headroom), and display support depended on the controller generation. It’s fine for dual-4K@60 and fast single NVMe drives, but heavy eGPU or multi-device RAID setups can bottleneck.
Thunderbolt 4 (same speed, much better guarantees)
Think of TB4 as “TB3 done right.” Intel certification standardized the floor: 32 Gbps PCIe guaranteed, dual-4K@60 minimum, wake-from-sleep, tighter cable rules. For mainstream docks, dual monitors, and fast SSDs, TB4 is rock-solid and widely available.
Thunderbolt 5 (the headroom play)
TB5 doubles tunneled PCIe to 64 Gbps and carries DP 2.1. Translation: faster multi-drive RAIDs, dramatically better eGPU headroom, and high-refresh multi-4K or multi-8K without weird compromises. Plus, up to 240 W charging means a true single-cable workstation for many big laptops.
USB4 (and USB4 v2)
USB4 overlaps Thunderbolt heavily, especially with v2 at 80 Gbps and DP 2.1 tunneling. The difference is certification and guarantees: Thunderbolt sets stricter, consistent minimums; USB4 can vary by vendor. If your USB4 laptop clearly states “80 Gbps” and DP 2.1, you’re in TB5-class territory for displays and strong for data.
Common workflows (what to expect)
| Workflow | TB3 | TB4 | TB5 | USB4 |
| External NVMe (single) | ~3,000 MB/s | ~3,000 MB/s | ~7,000 MB/s possible + headroom | ~3,000–7,000 MB/s (depends on version) |
| Multi-drive RAID enclosure | Often bottlenecked | Better, still tight under load | Smooth at high speeds | Varies (v2 is best) |
| Dual 4K monitors @60 | Usually OK | Guaranteed | Effortless; add a 3rd high-refresh | v1 OK; v2 excellent |
| eGPU frames vs desktop | ~60–70% | ~70–75% | ~85–95% (much closer) | v2 similar to TB5 potential |
| Charging a 16-inch laptop | Up to 100 W | Up to 100 W | 140–240 W | Up to 240 W |
Cable & connector quick guide
- Thunderbolt cables: Buy certified TB4 or TB5. Passive 0.5–1 m supports top link rates. Some older active TB3 cables cap at 40 Gbps.
- USB-C charging: For 100 W+, look for an E-marker; for 140–240 W, make sure the cable states USB PD 3.1 EPR.
- DisplayPort 2.1 cables: Use VESA labels—DP40 (UHBR10, 40 Gbps) or DP80 (UHBR20, 80 Gbps)—to match your resolution/refresh target.
Which should you choose?
- TB3: Still fine for budget docks, dual-4K@60, and basic fast storage—just check your laptop’s lane wiring and use good cables.
- TB4: Best all-rounder for most people today—reliable dual-4K desks, plenty of accessories, consistent performance.
- TB5: For eGPU users, creators with multi-4K high-refresh or multi-8K, and anyone who wants one-cable 140–240 W power plus top-end bandwidth.
- USB4: Great if clearly labeled—“USB4 80 Gbps” with DP 2.1 (v2) can match TB5 display headroom; otherwise expect TB4-like behavior.
Bottom line
Match the port to your workload. TB4 remains the safe, affordable choice for mainstream dual-monitor desks and fast SSDs. TB5 (and USB4 v2) unlock serious headroom for eGPUs, high-refresh multi-display setups, and big RAID jobs—plus real single-cable power for larger laptops. When in doubt, choose certified gear and the shortest quality cable you can run.
