It is common to hear Raspberry Pi owners want more USB ports. GetUSB.info just read about them introducing an official 4 port USB hub. Sweet. To note, most Raspberry Pi single-board computers, except for the Raspberry Pi Zero and A+ models, include a built-in USB hub that splits one USB connection into several USB Type-A ports. Just recently they launched the official Raspberry Pi USB 3 Hub, a high-quality USB 3.0 hub that offers four additional USB ports.

This hub includes a single upstream USB 3.0 Type-A connector with an 3 inches (8 cm) built-in cable. The “upstream” port is the socket used to communicate with the host device, which in this case is the Raspberry Pi. It also has four downstream USB 3.0 Type-A ports and can reach data transfer speeds up to 5 Gbps. There’s a USB-C socket for an optional external 3A power supply but that isn’t included with the $12 purchase. Quick note, the downstream port is are the sockets used to communicate with the devices, like a USB flash drive, hard drive, mouse, keyboard, printer, etc.

One driving force on why Raspberry Pi wanted to sponsor their own USB hub is the fact most ‘other’ hubs are just too expensive. One fundamental goal of Raspberry Pi is to provide an unparalleled offering for computer code development and the lowest possible price. Usually, you either pay a high price for a reliable, well-designed product, or you buy a cheaper option that’s unreliable, doesn’t work with various devices, or simply looks bad.

With this hub, there is no “race to the bottom,” where cheap, poor-quality products pushed out better options, and online marketplaces like Amazon became filled with low-quality hubs. To offer a better solution the Raspberry team got together with with Infineon to source a quality hub chip called the CYUSB3304.

Based on user beta testers and user comments here are the pros and cons of the Raspberry Pi USB 3 Hub:

The USB Mass Storage Device Protocol defines how USB devices which are attached to a host computer should interact (such as flash drives, external hard drives, and memory cards) and this protocol is critical for allowing stuff to talk with each other in the computer world. Here’s a breakdown of its core components:

In order for a USB flash drives to work interchangeably with other devices a universal standard must be created, defined and implemented for both device manufactures (the flash drives) and the host manufacturers (what flash drives are plugged into). The “Mass Storage Device” is the more technical term for what a USB flash drive is ( or USB hard drive or other memory storage device ) classified as. The classification spells out how communication works between the host computer and USB device.

The following information is a general outline and meant for non-technical readers to better understand the USB Mass Storage Device is. A link at the bottom will direct readers to a more technical resource, say someone reading up from a computer science class.

Let us start with the “Device Class and Protocol”

As mentioned the Mass Storage Class (also known as MSC) is a set of specifications which define a standardized way the USB device will present itself and communicate with the host (what it is plugged into); for example a computer, smartphone a car stereo or even the USB socket you find on a passenger plane. All of these “hosts” must conform to a specific way to communicate with the device.

Although we mention the USB socket of a plane, that particular situation doesn’t require “data transfer” and it’s only meant for power; although a specification is still required even when only dealing with power and/or charging. With that said, the most common protocol used for MSC devices is the “Bulk Only Transport” or BOT. The BOT is a method defining how data is either read or written from one device to the other. The BOT is designed to be fast and optimize data transfer while at the same time providing a reliable and stable code base for transferring data.

As a side note, the BOT was improved with UASP. The newer UASP (USB Attached SCSI Protocol) was introduced for the USB 3.0+ speed of devices. The UASP improves the older BOT by allowing faster data transfer rates and better performance to the devices which support the newer UASP.

So whether the host and attached device, say a USB flash drive, use BOT or UASP the commands used come from the SCSI (Small Computer System Interface) protocol. This protocol was developed in the late 1970s and ultimately introduced to the public for use in 1986. So the SCSI protocol has been around for a very long time.

One pillar of the SCSI protocol is the “block device” appearance of a device connected to a computer. This block device approach helps organize data and allows the two to communicate in blocks. Remember the most basic, 1024? the block device approach allows data transfer to work more efficiently and organized than other approaches.

The Mass Storage Device specification will classify data transfer speeds. This type of classification will setup the host computer and device on the best method to communicate. This is important because you want to define a Mass Storage Device’s ability to transmit data, during either the read or write operation, to an optimal speed for best performance. So for example, you don’t want a USB 3.0 hard drive communicating with the host computer at USB 2.0 speeds. The classification for data transfer will sync up the proper protocol.