Thunderbolt 5 doubles Thunderbolt 4's bidirectional data transfer, offering 120Gbps in one direction and 40Gbps in the other, alongside 240 watts of power delivery. Both standards use USB-C connectors and support docks, external storage, and displays, with Thunderbolt 5 maintaining backwards compatibility with Thunderbolt 4, 3, and USB4 devices. However, connections operate at the speed of the slowest component. For most users, Thunderbolt 4 remains sufficient for routine backups, fast external SSDs, charging, Ethernet, and single- or dual-monitor setups.

Thunderbolt 5's 80Gbps baseline bandwidth benefits data-heavy workflows, such as moving enormous files or using advanced docking stations. It also improves display support, enabling multiple 4K displays at higher refresh rates or certain 8K configurations, whereas Thunderbolt 4 supports one 8K or two 4K displays at 60Hz. Actual performance depends on display-compression support, monitors, and operating systems.

On charging, Apple's Thunderbolt 5 Pro cable supports 240W versus Thunderbolt 4's 100W, benefiting high-end gaming laptops like the Lenovo Legion 9i Gen 10 (140W) and Razer Blade 18 (100W) if their ports support it. Apple's Thunderbolt 5 Pro cable is 1 meter and $69 (passive), while Thunderbolt 4 Pro cables are 1.8m ($129) and 3.0m ($159) with active circuitry. Mainstream buyers should stick with Thunderbolt 4 for broad accessory compatibility.