USB-B vs. USB4
Comparing 2 standards across 8 specifications. 8 key differences identified.
USB-B (Standard-B) is the squarish connector historically used on printers, scanners, and external hard drives -- the peripheral-side counterpart to USB-A. A 9-pin SuperSpeed variant with a distinctive stacked upper tab was added for USB 3.0, though USB-C has since displaced Standard-B in most new peripheral designs.
USB4, released August 2019, is built on Intel's Thunderbolt 3 protocol, donated to USB-IF as the new foundation -- up to 40 Gbit/s, a mandatory USB-C connector, and tunneling that lets a single port carry USB, DisplayPort, and PCIe traffic at once. Thunderbolt 3 compatibility is required; Thunderbolt 4 compatibility is optional for device makers.
Specification Comparison Table
8 Parameters| Parameter / Spec | ||
|---|---|---|
|
Pin Count
|
4 (USB 1.x/2.0) or 9 (USB 3.0+, stacked SuperSpeed tab) | — |
|
Standard Base Dimensions
|
~11.1 x 7.0 mm | — |
|
Reversible
|
No | — |
|
Typical Role
|
Peripheral-side port (printers, scanners, external drives) | — |
|
Released
|
— | August 2019 |
|
Max Bandwidth / Data Rate
|
— | Up to 40 (Gen 3x2) or 20 (Gen 3x1) Gbit/s |
|
Connector Required
|
— | USB-C only |
|
Protocol Foundation
|
— | Intel Thunderbolt 3 (donated to USB-IF) |