Maximum cable length for USB devices

USB is an exceedingly popular connector. Over the new MacBook, the only connector one comes across is the USB-C, two of them. They are powerful connectors, powered by the Thunderbolt 3 technology. One can access the functionality of different ports such as HDMI, USB-A, and DisplayPort using the two Thunderbolt 3 ports over MacBook. This is with the use of a USB-c hub with HDMI, which is a multiport adapter.[ laptop desk riser]

USB-C is also a very useful port. It enables a range of functionalities, such as connecting external hard drives and charging mobile phones.

The first USB cables that we had come across were USB 1.0/1.1. USB 2.0 cables then came into the scene and took over the functionality of USB 1.0/1.1 nearly in its entirety. USB 3.0/3.1 is the newer standard that we nowadays use. But this is yet to become as popular as the USB 2.0 standard. Many people still use USB 2.0 devices, ports, and cables.

There is a mistake that people normally make while using USB 2.0 devices. They attempt to bring about a significant change in the length of the cable of the device that they purchase. Let us suppose that the device that they are using has a 10 feet cord. Sometimes the users purchase a 10 feet extension. This makes the total cable length to be 20 feet.

This nature of arrangement will cease to operate in many cases because it requires a special kind of USB cable, also known as a repeater or active cable.

Let us address an important matter of concern at this point, which is how long USB cables can be at the maximum?

USB 2.0 cable

Let us consider the maximum length that a USB 2.0 cable can have. Going by the 2.0 specifications, the length of the cable that connects USB 2.0 devices, both hi-speed and full speed, shout be 5 meters at max. 5 meters equals 16 feet and 5 inches. [usb c multi hub]

Henceforth, connecting a bunch of extension cables is an arrangement that will not work. A user is likely to encounter connectivity and speed problems if he creates a cable of 30 feet using extensions and uses it to connect two USB 2.0 devices placed in different rooms.

But since the maximum length of the cable can be 16 meters, a user can connect two cables, one 10 feet in length and the other 6 feet, such as a USB hub with a long cable. This should make a feasible working arrangement.

USB 3.0/USB 3.1 cable

In the 3.0/3.1 specification, the maximum cable length has not been specified. If we take a look at the USB 3.0/3.1 devices, which are SuperSpeed or SuperSpeed+, the recommended length is 3 meters, which is about 9 feet and 10 inches.

The issue that however arises, in this case, is that the quality of the data transmission is negatively affected as we increase the cable length. Even while the results may be variable, but in most cases, the data signals are strong if a high-quality cable is used, even while it may be 3m in length.

In case one uses a cable that is longer than 10 feet, one should use an active cable.

Breaking length limitations of USB cables

USB specs limit the length of cables, but there is a way to extend the limitations. For the same, one either has to use repeater (active) cables or self-powered USB hubs.

In case one feels the need to go for long cables when using the MacBook, one should invest in a self-powered USB-c hub with HDMI. However, using both options, repeater cables, and self-powered USB hubs come with their unique limitations.

Other options at a users’ disposal are to use a USB over Ethernet or using a USB bridge, which further extends the USB range.

USB hubs

For extending the range of your USB device, self-powered USB hubs, such as a USB-c hub with HDMI may be used along with extension cables. One alternately has a choice at using a self-powered USB hub with long cable.

A user has to nevertheless keep in mind that when he uses 2.0 hubs, the distance between any two powered hubs may not be longer than 5 meters, which is 16 feet and 5 inches.

In a similar way, when using 3.0/3.1 hubs, one should not exceed 3 meters in length, which is the recommended length. 3 meters is 9 feet and 10 inches.

One also has a choice of using bus-powered USB hubs. But this comes with the disadvantage that one runs out of power upon extending one’s setup.

Repeater (Active) Extension cables

USB repeater extension cable would have the mechanism for regenerating the USB signal. Active cables are, in most cases, 1 port USB hubs.

A regular USB cable may be used together with an active cable. But for the same, the regular cable may not be more than 5 meters, which is 16 feet and 5 inches, in the case of USB 2.0 devices. It may similarly not be more than 3 meters, which is 9 feet and 10 inches, for 3.0 devices.

Characteristically, active cables are bus-powered cables. For receiving the full 500mA power which the USB port has, one could invest in an active cable that features a separate power adapter.

There is a limit to how long the regular USB cables can be. But there are also some limitations over how long active cables can be, and the number of USB hubs, such as USB-c hub with HDMI that one can use.

There is a method that allows one to extend a USB signal to go beyond 30 meters. By using a USB over Ethernet, the signal can extend for 100 meters, which is around 328 feet.

Similarly by creating a USB bridge, one can transmit data across different communication channels, like wireless methods.

USB 1.0/1.1

Being backwards compatible, USB 2.0 cables work with all USB 1.0/1.1 devices. The limitation for USB 1.0/1.1 cable is 3 meters. The total length of the cable similarly should not exceed 18 meters or 59 feet at maximum. This is when one uses a 1.0 /1.1 USB host and device.