Chapter in this post:
Question: I have an external hard drive that I would like to put away from my Mac. In stores you can find USB cables in lengths of 0,9 m, 1 m, 1,5 m, 2 m, 3 m and even 5 m. My question is: What is the maximum length of a USB cable?
Answer: The answer was not that easy, because there are lively discussions on this topic in various forums. I find it striking that normal USB cables (regardless of whether USB 2 or USB 3) are only available in lengths of up to 5 meters. According to Wikipedia, this is also the maximum length of a USB cable before it should end in a USB device or a USB hub. Wikipedia says under USB hubs / general this excerpt: "The maximum distance between two USB-connected devices is 5 m due to the limitation of 30 m per USB cable - six cables each five meters long and five hubs in between." This means that you should definitely choose a cable no longer than 5 meters if you don't want to run the risk of data transfer between the computer and the USB device (such as a [USB hard drive-> external USB hard drive]) should not be disturbed, very slow or riddled with data errors.
Update 10-2016: I have a new post on the topic "USB extension"if you are interested in the topic. Solutions up to 50 or 60 m transmission distance are also presented there.
There are still exceptions. For example, you can do one USB Hub after the 5 meters of cable install and then extend the connection by another 5 meters. According to Wikipedia, the game can be played with up to 6 cables and 5 hubs, so that in the end you get to a proud 30 meters.
The other solution is [active USB-2 cable-> USB-2 extension], which have a built-in repeater for signal amplification. These cables then usually have a USB Type-A connection with a USB plug on one end and a USB socket on the other end of the cable, so that the actual USB cable can be plugged into this USB extension. With the built-in repeater, cable lengths of 10 m, 15 m and even 20 m are possible. However, if external hard drives are to be connected after this length, you first have to connect an active USB hub with its own power supply to the end and then plug in the external hard drive.
A active USB 3 cable However, it is only found up to 5 m. Larger distances are probably not technically feasible there because of the high data rate.
A corresponding active USB 3 hub that does its job well on the Mac is, for example, that of Anker. It also understands USB 2 and can also supply USB 3 devices with data in parallel. It is important that the USB 3 devices are not slowed down if you also plug in a USB 2 device, because this is the case with some hubs.
Longer cables of 10 m and more are only available up to the USB-2 standard
If you only work with USB 2 cables, you of course only need an active USB 2 hub. Here you can recommend Belkin’s:
Jens has been running the blog since 2012. He appears as Sir Apfelot for his readers and helps them with problems of a technical nature. In his free time he drives electric unicycles, takes photos (preferably with his iPhone, of course), climbs around in the Hessian mountains or hikes with the family. His articles deal with Apple products, news from the world of drones or solutions for current bugs.
The page contains affiliate links / images: Amazon.de