Not Just a Symbol — What the Lightning on a USB Cable Means.

The universal USB standard has gone through so many versions over three decades that choosing the 'right' cable has become a puzzle. The lightning symbol on the connector is a hint that will help not to make a mistake with speed and connection capabilities.

What the Lightning Symbol Means on USB Cables

USB-C has gradually become dominant at both ends of the cable, simplifying life for users. However, among the high-quality modern cables, there are models with a lightning logo — this is a sign that you have a Thunderbolt cable compatible with USB-C. The number next to the symbol indicates the generation of the standard and the maximum speed.

Until 2015, Thunderbolt used the Mini DisplayPort connector, and starting with Thunderbolt 3, it switched to USB-C. The current version, Thunderbolt 5, provides 80 Gbps in both directions, and in Bandwidth Boost mode — 120 Gbps in transmission and 40 Gbps in reception. The standard also offers 64 Gbps PCI Express lanes and networking capabilities at the same speed.

For ordinary users, the clear advantage of Thunderbolt 5 is cost-effective and fast memory expansion. For instance, Mac mini owners can add an external SSD with a throughput close to that of the internal drive, avoiding expensive factory upgrades.

It is worth noting that USB flash drives can noticeably heat up during data transfer — this is normal, as all work occurs within the chip without any moving parts. However, excessive heat sometimes signals technical failures or a low-quality drive.

We have also noted that for fast file transfers between devices, it is most convenient to use a USB drive. But when choosing cheap models, it is essential to remember that instead of help, they may cause many problems.

Decades of USB standard development have led to the emergence of various versions and cables, but fortunately, the lightning symbol on the connector helps to understand their characteristics. Thunderbolt 5 cables turned out to be particularly useful for additional memory expansion, allowing users to effectively use their devices without excessive costs. It is also important to choose quality cables and drives to prevent overheating and technical issues.