# USB 3 Standard-B connector > a class of legacy USB connectors that preceded USB-C (“B” indicating the peripheral device end) **Wikidata**: [Q133458632](https://www.wikidata.org/wiki/Q133458632) **Source**: https://4ort.xyz/entity/usb-3-standard-b-connector ## Summary The USB 3 Standard-B connector is a class of legacy USB connectors designed for the peripheral device end of a cable, distinct from the host ("A") end. It served as the standard interface for high-speed peripherals before being superseded by the USB-C connector type. This connector class encompasses both the plug and receptacle forms and is recognized by various names including USB 3.0, USB 3.1, and USB SuperSpeed Standard-B. ## Key Facts * **Classification:** It is a subclass of both the "USB Standard-B connector" and the "USB 3 Standard Type-B connector." * **Successor:** The connector class has been replaced by **USB-C**. * **Function:** The "B" designation indicates its specific role as the peripheral device end of a connection. * **Components:** The class includes the **USB 3 Standard-B plug** and the **USB 3 Standard-B receptacle**. * **Official Name:** The official name is cited as **USB 3.1 Standard-B connector** per USB Implementers Forum documents. * **Aliases:** Also known as USB 3.0 Standard-B, USB SuperSpeed Standard-B, USB SS Standard-B, USB 5Gbps Standard-B, and USB 10Gbps Standard-B. * **Standards Body:** Regulated by the **USB Implementers Forum**. * **Distinct From:** It is structurally and functionally different from the USB Powered-B connector, USB 3 Standard-A connector, USB 3 Micro-B connector, and USB 2 Standard-B connector. ## FAQs ### Q: What is the USB 3 Standard-B connector used for? A: It is a class of legacy connectors used at the peripheral device end (the "B" end) of a USB cable. It was commonly used to connect devices like hard drives and printers to hosts before the adoption of USB-C. ### Q: What replaced the USB 3 Standard-B connector? A: The USB 3 Standard-B connector was replaced by **USB-C**, which serves as the modern standard for both hosts and devices. ### Q: Is a USB 3 Standard-B plug the same as a USB 2 Standard-B plug? A: No, while they share a general "Standard-B" classification, the USB 3 Standard-B is distinct from the USB 2 Standard-B connector and is listed specifically as a separate entity. ### Q: Why does this connector have names like "5Gbps" and "10Gbps"? A: These aliases refer to the data transfer speeds associated with different iterations of the standard (such as USB 3.0 and USB 3.1), under which this connector class was defined. ## Why It Matters The USB 3 Standard-B connector represents a critical phase in the evolution of connectivity, serving as the primary bridge for high-speed peripherals during the transition from USB 2.0 to the modern USB-C era. As the "SuperSpeed" variant of the classic Standard-B shape, it enabled significantly higher data transfer rates (indicated by its 5Gbps and 10Gbps aliases) required by external storage drives and high-bandwidth devices. Its significance lies in its specific role within the USB architecture: defining the "peripheral device end." This distinction maintained the strict host-to-device topology of legacy USB systems. However, its existence also highlights the complexity of the pre-USB-C landscape, where different speeds and power requirements necessitated distinct connector shapes (Standard-A vs. Standard-B vs. Micro-B) compared to the reversible, unified USB-C standard that eventually replaced it. ## Notable For * **Peripheral Interface:** Being the dedicated "device end" connector for USB 3.0 and 3.1 protocols. * **Naming Complexity:** Existing under multiple official and unofficial names, including USB 3.0, USB 3.1, SuperSpeed (SS), and speed-based designations (5Gbps/10Gbps). * **Predecessor to USB-C:** Serving as the final "Standard-B" form factor generation before the industry shifted to the symmetrical USB-C standard. * **Distinct Form Factor:** Being specifically differentiated from the smaller "Micro-B" and the powered-specific "Powered-B" variants. ## Body ### Definition and Taxonomy The **USB 3 Standard-B connector** is defined as a class of legacy USB connectors. Taxonomically, it is a subclass of the **USB Standard-B connector** and the **USB 3 Standard Type-B connector**. It is distinguished by its role in the connection hierarchy: the "B" designation explicitly indicates it is the **peripheral device end**, as opposed to the host end. ### Components and Variants This connector class manifests in two physical components: * **USB 3 Standard-B plug:** The male connector attached to the cable. * **USB 3 Standard-B receptacle:** The female port located on the peripheral device. The connector is referred to by a wide range of aliases that reflect its evolution through different USB specifications. These names include **USB 3.0 Standard-B**, **USB 3.1 Standard-B** (cited as the official name in 2022 documentation), **USB SuperSpeed Standard-B**, **USB SS Standard-B**, **USB 5Gbps Standard-B**, and **USB 10Gbps Standard-B**. ### Historical Context and Differentiation The USB 3 Standard-B connector is categorized as a **legacy** technology that **preceded USB-C**. It is managed by the **USB Implementers Forum**. While it shares the "Standard-B" naming convention with the **USB 2 Standard-B**, it is explicitly categorized as **different from** its USB 2 predecessor. Additionally, it is distinct from the **USB 3 Standard-A connector** (host end), the **USB 3 Micro-B connector** (mobile devices), and the **USB Powered-B connector** (which added extra pins for power). ## References 1. [Source](https://www.usb.org/document-library/usb-31-legacy-cable-and-connector-revision-10) 2. [Source](https://www.usb.org/document-library/usb-type-cr-cable-and-connector-specification-release-24) 3. [Source](https://www.usb.org/document-library/usb-32-revision-11-june-2022) 4. [Source](https://www.usb.org/document-library/usb-type-cr-connectors-and-cable-assemblies-compliance-document-rev-21b) 5. [Source](https://www.usb.org/document-library/universal-serial-bus-31-legacy-connectors-and-cable-assemblies-compliance-document)