USB4 vs Thunderbolt 5 Compared

Two cable standards, two sets of speed claims, and a lot of overlapping ports that look identical. Here's what actually separates them.

The short version

USB4 Version 2.0 and Thunderbolt 5 are closely related standards that both use the same USB-C connector and both top out at similar headline speeds, but Thunderbolt 5 is a stricter, certified specification with guaranteed minimums, while USB4 v2 is a looser spec that manufacturers can implement at different tiers. In practice, a "USB4" port on a budget laptop may run meaningfully slower than a Thunderbolt 5 port on a premium one, even though both use the same cable.

Speed and bandwidth

Thunderbolt 5 supports up to 80Gbps bi-directional, with a boost mode pushing up to 120Gbps for display-heavy tasks by borrowing bandwidth from the return channel. USB4 v2 also specifies up to 80Gbps, but many real-world USB4 v2 implementations ship at lower tiers — 40Gbps is common — because the spec allows manufacturers to implement a subset rather than the full ceiling.

For everyday tasks like transferring photos or backing up a phone, both standards are already far beyond what you'll notice. The gap shows up with external SSDs rated for sequential speeds above 2,000MB/s, multiple 4K/8K displays, or eGPU setups — Thunderbolt 5's guaranteed minimums make it the safer bet for those workloads.

Certification and guarantees

This is the biggest practical difference. Every Thunderbolt port and cable must pass Intel's certification program, which guarantees a specific minimum performance and full compatibility with Thunderbolt docks, eGPUs, and daisy-chained displays. USB4 ports don't require the same certification, so two devices both labelled "USB4" can behave differently — one might not support external GPU pass-through, or might drop to USB 3.2 speeds when running two displays at once.

If you're buying a dock, external monitor, or eGPU enclosure and want it to "just work" across different laptops, Thunderbolt certification is the more predictable choice.

Which NZ laptops support each

MacBook Pro and MacBook Air models (M-series chips) use Thunderbolt, with recent Pro models supporting Thunderbolt 5. On the Windows side, Dell XPS, HP Spectre/EliteBook, and Lenovo ThinkPad ranges increasingly ship Thunderbolt 5 or Thunderbolt 4 ports on higher-end configurations, while more budget-focused laptops from the same brands often list "USB4" or even plain USB-C 3.2 instead. Retailers like PB Tech, Noel Leeming, and Harvey Norman list the specific port standard in the spec sheet — worth checking line by line rather than assuming from the connector shape alone.

Do most buyers need to care

For general use — browsing, office work, streaming, charging — the difference between USB4 and Thunderbolt 5 is invisible. It matters if you're a video editor working off external SSDs, someone running multiple high-refresh external monitors from a single cable, or connecting an eGPU. For those users, paying extra for a laptop with confirmed Thunderbolt support (not just "USB-C" or unlabelled "USB4") avoids compatibility headaches down the track.

Buying tips

• Check for the literal words "Thunderbolt 4" or "Thunderbolt 5" on the spec sheet — "USB-C" alone tells you nothing about speed.
• Cables matter too — a passive USB-C cable rated for charging won't hit either standard's top speeds; you need a certified 80Gbps-rated cable.
• Docks and hubs bought for Thunderbolt 5 will generally work fine on USB4 ports too, just at reduced speed.