If you’ve spent time shopping or researching new consumer gadgets you will have heard about the new USB ports and standards. There’s USB 3.0 and 3.1, and then there’s something called USB-C, officially known as USB Type-C. You may be wondering what these are, whether they are the same thing, and what the difference is. How is USB 3.1 different from USB 3.0 or even 2.0? The USB, or Universal Serial Bus, is a port standard that has been around for nearly 20 years and is the most widely used. As there are so many devices that support USB, keeping up to date on the latest developments in this port, cable and standard is important.
There are multiple improvements in the trusty USB port we’ve been using for so long. I’m sure we’ve all had difficulty plugging in a cable or flash drive because we’ve had it upside down. The new USB Type-C cable and port is reversible, so there is no “up” or “down,” and you can plug it in either way. There are other new features in USB, too, like ultra-fast data transfer speeds up to 10Gbps, and up to 100W of power – enough to charge a laptop, and even adding an HDMI or DisplayPort video signal into a single cable.
This sounds great! A single, easy-to-use cable that powers your laptop, brings a video signal to a monitor, and splits into a hub letting you use other USB devices. However, it is important to know that each of these improvements is a separate specification, and device (and cable) manufacturers could choose to integrate one, two or all of them. The reversible cable is a feature called USB Type-C, or USB-C. The ability to provide 100W of power is called USB Power Delivery or USB PD. Fast data transfer speeds is a specification called USB 3.1 or USB 3.1 Gen2, while the integration of DisplayPort is it’s own feature. If these are important to you (and they should be) be very careful to read the documentation of the products you’re purchasing.
USB 3.1 vs USB Type-C – Standard vs Port
Before we go any further, it’s important to note the difference between standards (like USB 3.1, 3.0 and USB 2.0) and ports or plugs (like USB Type-A, Type-B or Type-C). The version of the USB standard (3.1, 2.0, etc.) indicates the speed and the function of the cable. The USB Types are the shape of the cable plugs and the shape of their ports in your computer or device. There are many kinds, most of which you probably already know.
USB Type-A is the familiar rectangular port. It is the largest USB port and is often found on computers and car chargers. The device that has the USB Type-A port is almost always the host device, a.k.a. the main device that is accepting other devices, providing the electricity, and controlling the data transfers. Examples of host devices with USB Type-A ports include desktop computers, laptops, custom gaming PCs, and even routers, gaming consoles and televisions.
The USB Type-B port is a blocky, square-shaped plug that is often used on external hard drives and printers. There are also mini and micro USB Type-B ports that are commonly found on portable devices: smartphones and tablets these days usually have micro USB, while mini USB ports tend to be on things like cameras and older devices. The micro USB port is predictably smaller than the mini USB port. Probably the weirdest type of USB cable is the Micro-B USB 3.0, sometimes called the extended USB micro Type-B. This type of connection is used to provide the faster data transfer rate that USB 3.0 provides (that regular micro or mini USB don’t) while also allowing a standard micro USB to be used for charging,
There is an old specification of USB called USB On-The-Go, or USB OTG, that allowed USB devices such as phones and mp3 players to act as a host and receive other USB devices like mice, keyboards or flash drives. This means that a phone with USB On-The-Go could act as a peripheral when attached to a computer, or as a host device when attached to a keyboard, using the same port.
USB Type-C, sometimes referred to as USB-C, is simply a new shape of port and cable plug. There are many benefits of the new USB Type-C port. The first of which is reversibility. The difficulty of plugging in a USB device is a universal staple of Internet humor. Even when looking it is not easy to plug in a USB cable correctly. Since the new USB Type-C connector is reversible, you can plug it in either way – upside down or right side up, it doesn’t matter. Also, if you have a computer and a device that both have USB-C ports you can plug either end of the cable into the PC, and the other in the peripheral.
USB Type-C is also about the same size as micro USB connections, so it’ll fit in even the smallest of devices. Furthermore Type-C USB is also great for charging. Bi-directional power means that not only can your device charge a peripheral, but if it runs low, the peripheral could charge the host device.
When USB Type-C is combined with USB Power Delivery (or USB PD) it can support a much higher power output – up to 100W at 20V and 5A. This is not only enough to charge smartphones and tablets, like we’ve been doing with micro USB, but you can now charge a notebook with USB PD and Type-C. This adds even more confusion because some USB 3.1 ports have the 100W Power Delivery feature, while others do not, and some USB 3.0 cables have it, and some do not. Some new laptops like the Apple MacBook and Google Chrome Pixel have such ports for charging. This also means that devices like hard drives and USB hubs won’t need a separate power cable, which will cut down on cables and clutter. I’m looking at you, laptop stand.
USB 3.1 vs USB 3.0 vs USB 2.0
It’s hard to believe it, but USB 3.0 was introduced over half a decade ago, in November of 2008. The then-new USB 3.0 significantly increased the speeds of data transfer. USB 2.0 was only capable of a theoretical maximum data transfer rate of 480 megabits per second, while USB 3.0 was capable of 5 gigabits per second, or over 10 times faster. At the time not many computers had USB 3.0 ports, and some only had a few alongside USB 2.0 ports. To distinguish between USB 2.0 and 3.0, the USB 3.0 ports had a blue connector or tongue inside.
USB 3.1 was released just a few years ago, in July of 2013. Since then, device manufacturers have been working feverishly to bring the new standard to the products in your home. The data transfer speed of USB 3.1 is incredible – 10Gbps. This rivals the speed of Ethernet and the original Thunderbolt. However, there are few devices that are capable of such high data transfer speeds. Current SSDs have transfer rates that can push USB 3.0 to its limits, but not 3.1 (yet). To learn more about SSDs, see our blog post, What is an SSD?
Remember that the version of USB (3.1, 2.0, etc.) describes the data speed and power supply (kind of – see below) specifications of a cable or connection, while the type of USB (A, B, C) describes the physical shape of the port and connector. So a traditional Type-A connector can accept USB 3.1, 3.0, 2.0 and even 1.0 cables and devices, regardless of which version of USB the port supports. The lowest version of USB among the cables and devices will determine the data transfer speed on a port-by-port basis.
Stewart, in one of the comments below, had a great explanation. If you have a computer with USB 3.0 ports and you have a USB 3.1 hard drive, a USB 3.0 hard drive and a USB 2.0 webcam connected, the hard drives will both operate at USB 3.0 speeds, while the webcam will operate at USB 2.0 speeds. The webcam is bottlenecked down its USB 2.0 speed, while the USB 3.1 hard drive is bottlenecked down to the computer’s USB 3.0. If you have a USB 2.0 hub connected to a USB 3.0 device and to your USB 3.0 computer, the hub is the bottleneck, limiting speeds to USB 2.o. Keyboards and monitors often have USB hubs built in, so it’s important to make sure you know what data transfer speeds they support before plugging in your thumb drive, USB WiFi adapter or other speed-sensitive device.
USB 3.1 Gen 1 vs Gen 2 – USB 3.0 has been renamed USB 3.1 Gen 1
Similarly, a USB Type-C port may support USB 3.1, 3.0 or even USB 2.0, so just because you see the new port, doesn’t mean that it can transfer data at high speeds or provide 100W of power. When you see the term USB 3.1 Gen 1, this is just a fancy name for USB 3.0, and provides speeds up to 5Gbps. USB 3.1 Gen 2 is the new name for USB 3.1 which provides speeds up to 10Gbps. Confused yet? It can certainly be hard to tell if your computer has USB 3.1 Gen 1 or USB 3.1 Gen 2 ports.
USB 3.0 and USB 3.1 are almost the same thing. The USB Implementers Forum, the group responsible for developing, publishing, and certifying USB ports and standards has said that “the USB 3.1 specification absorbed USB 3.0, meaning the terms USB 3.0 and USB 3.1 Gen 1 are synonymous.” For marketers of products this is a wonderful news, but for consumers it is just additional confusion. In marketing materials USB 3.1 Gen 1 (or Rev1) is referred to as SuperSpeed USB or just SuperSpeed; while USB 3.1 Gen 2 (or Rev2) is referred to as SuperSpeed USB 10Gbps, or “SuperSpeed +.” The USB logo on the product will be surrounded by a battery if it has the USB Power Delivery 100W feature.
Backwards Compatibility and your Custom Computer
If you’re concerned about your beloved older camera or joystick becoming unsupported by the new USB standards and ports, don’t worry. Every Type-A USB port is backwards compatible with previous standards. You can plug in your USB 2.0 webcam from 10 years ago into any USB Type-A 3.1, 3.0 or 2.0 port and it will work. You won’t get the fast data transfer speeds of the new standards, but you won’t have a problem using the device. That is assuming you can find drivers for your modern operating system.
Likewise, there’s no reason to worry about moving to USB Type-C and losing support for all of your USB devices. You’ll need some kind of adapter, but there’s no reason you won’t be able to plug in a USB hub into your USB Type-C port and have space for multiple Type-A ports.
Thunderbolt, DisplayPort and more
Thunderbolt is a competing interface, originally developed by Intel and Apple, allowing peripherals to be connected to a computer. The original Thunderbolt was capable of a transfer rate of 10Gbps, the same as USB 3.1. The newest version, Thunderbolt 3, is capable of 40Gbps transfers. Thunderbolt 2.0 incorporated DisplayPort 1.2, allowing for video streaming to a 4K display. Interestingly, Thunderbolt 1 and 2 shared the mini DisplayPort (mDP) connector, and were commonly found on Apple laptops.
The new Thunderbolt 3.0 uses the same connector and port as USB Type-C. Historically Thunderbolt had limited adoption, even though it has better performance than USB, because of high costs, expensive cables, and limited manufacturer support. Not only is Thunderbolt 3.0 much faster than USB 3.1, it offers this boost in performance using the reversible Type-C USB port. What this means is that if you have the right device, you can now run USB 3.1, Thunderbolt, DisplayPort, PCI-Express and charge your device over a single cable from a single port. You could even use a simple adapter or cable to convert a video signal from the USB-C to HDMI, because DisplayPort can easily be converted to HDMI. See our earlier blog post on DisplayPort vs HDMI. This makes it especially attractive to users who would otherwise use a laptop dock.
A Thunderbolt icon (a lighting bolt) will be used on the device itself to tell you whether the USB-C port supports Thunderbolt. Another way to check is if to see if the Intel Thunderbolt 3 Controller (sometimes called Alpine Ridge or “Thunderbolt(TM) Controller -1577”) is included in your Device Manager [Thanks van77!]. There is plenty of confusion among both manufacturers and online retailers, as it is still early in the adoption cycle.
Overall, the convergence of connectors should make all of our digital lives less cluttered and simpler. Although the transition may be messy and confusing, it is certainly worth it for the future of custom computers. Imagine plugging a single cable from your custom computer into a secondary monitory at your desk, and receiving charging power, an Ethernet adapter, and multiple USB ports for external mice and keyboards. The USB Type-C port and the USB 3.1 specification were developed and released at roughly the same time, so it is easy to confuse them. Remember that Type-C USB is a small reversible plug connector and port, while USB 3.1 (Gen 2) is the specification that determines the speed of data transfer.