Friends, when buying a new computer, are you confused by the various interfaces? Don’t worry, today we will talk about those dazzling interface technologies: Thunderbolt 4, Thunderbolt 3, USB 4, and USB 3. Understand the differences and you’ll be able to make a more informed choice the next time you upgrade your device.
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Comparison of Thunderbolt 4 vs Thunderbolt 3
Thunderbolt is a unique technology developed by Intel, with participation from Apple. It’s more of a brand name than a specification, and Intel has been pushing the technology in MacBooks since 2011. Thunderbolt 4 has completely replaced Thunderbolt 3 after its launch in 2020. It supports the USB 4 specification, DisplayPort 1.2 and PCIe. Thunderbolt 4 is compatible with almost every other device, including all Thunderbolt versions and USB.
Thunderbolt 4 continues to rely on the flexible USB-C form factor and has 40 Gbps bandwidth. Many of its features and minimum performance levels already exceed Thunderbolt 3. Thunderbolt 4’s minimum video support has improved compared to Thunderbolt 3, with the new standard now supporting at least two 4K displays running at 60Hz or one 8K display running at 30Hz.
PCIe bandwidth requirements double, taking Thunderbolt 4 from Thunderbolt 3’s 16 Gbps to 32 Gbps. If you use removable storage regularly, you should be able to theoretically increase transfer speeds via Thunderbolt 4 to around 3,000 MB/s. The best Thunderbolt 4 docking stations can provide up to three downstream Thunderbolt 4 ports and are Direct Memory Access (DMA) protected with Intel’s virtualization technology to help combat threats.
USB 4 is a high-performance USB standard
USB 4 is the latest Universal Serial Bus (USB) standard, named by USB-IF. Previous USB versions have gone through USB 3.1 Gen 1 to USB 3.2 Gen 1 (5Gbps), USB 3.1 Gen 2 to USB 3.2 Gen 2 (10Gbps). There is also a newer USB 3.2 Gen 2×2 standard with speeds up to 20Gbps and support for corresponding hardware. USB 4 is now backward compatible with USB 2.0.
USB 4 is built on Thunderbolt 3, so it has many of the same capabilities. USB4 benefits from Intel abandoning Thunderbolt 3 licensing. USB4 is built on Thunderbolt 3, so many of their features are similar. The best version of USB 3.0 reaches speeds of 20Gbps, and USB4 has the same speed as Thunderbolt 3 and 4, which are both 40Gbps. USB4 strictly uses the USB-C interface.
Previous versions of USB split bandwidth among all connected devices and relied on lane transfers of data and video, with no crossover. USB4 allows lanes to be shared on demand, allowing you to reach bandwidth caps such as with the best laptop docking stations. USB4 can handle dual 4K displays or a single 5K display, as well as up to 100W of charging power, the same as Thunderbolt 3. The main conclusion is that USB 4 hopes to unify ports between devices. It’s time for everything to switch to USB-C with performance equivalent to Thunderbolt 3.
What is the difference between Thunderbolt 4 and USB 4?
There are four different versions of the latter standard, although the ones we mainly see are USB 4 Gen 2×2 and USB 4 Gen 2×3, known as USB 4 20 Gbps and USB 4 40 Gbps respectively. USB4 only needs to reach 20 Gbps and does not need to support the lowest display resolution. The data only needs to reach at least 10 Gbps through USB 3.2; while Thunderbolt 4 guarantees 10 Gbps and 32 Gbps PCIe performance through USB 3.2.
USB4’s port power requirements are reduced to a minimum of 7.5W, while Thunderbolt 4 guarantees 15W. Thunderbolt 4 and USB4 are compatible with each other, but Thunderbolt 4 guarantees a certain level of performance.
THUNDERBOLT 5 is in sight
Thunderbolt 5 is expected to appear in some devices in 2024, bringing significant improvements over the previous generation. Intel outlines the expected improvements in the chart below. The biggest change is a huge increase in bandwidth, with Thunderbolt 5 doubling Thunderbolt 4’s 40Gbps capability. The new standard is 120Gbps, with flexible bandwidth that can handle up to 80Gbps bidirectional transmission or 120Gbps transmit and 40Gbps receive simultaneously.
Thunderbolt 5 can provide more external display support, running up to three external displays on a single cable, with high resolutions and refresh rates. Thunderbolt 5 can also handle up to 240W of charging power back to the host PC, easily exceeding Thunderbolt 4’s current 100W cap. This should make it more suitable for power-intensive gaming laptops and workstations.
Thunderbolt 5 will allow easy connection with external GPUs. Even if you don’t have an AI PC, you can connect a discrete GPU (great for gaming too). Thunderbolt 5 is compatible with USB4 and will be backward compatible with older Thunderbolt standards (although performance will be reduced when connecting to PCs that don’t have Thunderbolt 5).
