There are many ways nowadays that we can interact with a computing system.
Peripherals are input and output devices that get connected to a computing system that enables us to put information into it (via inputs) as well as get information out of it (via outputs).
There are many ways peripherals get connected to a computing system but, one of the most utilised methods for communication is Universal Serial Bus (USB).
Computing systems have USB ports that peripherals get plugged into.
However, computing systems are limited by how many USB ports they have.
USB Hubs enable you to extend the total number of USB ports.
But, sometimes one USB Hub is not enough.
So, can you plug one USB Hub into another?
Yes, you can plug one USB Hub into another. A USB Hub is essentially a USB device in itself and is why you can plug it to another USB Hub to add more ports. However, there are some factors to take into consideration before doing so which will be covered in this article.
Why it is possible to plug a USB hub into another
Let’s take a deeper look at the USB hub and why it is possible to plug one into another.
In the earlier days of computing, you might have been restricted to only two or three devices that you connect as an input or output.
This might have been a mouse to help you scroll, a keyboard to help you type characters and a monitor to help you view information.
But, over the years computing has evolved along with the number of inputs and outputs.
Now you have a multitude of devices you can connect to help you achieve different tasks. Below are just some to name a few;
- Printer
- Scanner
- Webcam
- Microphone
- Midi Controllers
- Gaming controllers
Universal Serial Bus
Another thing that has evolved over the years is how these peripherals communicate with a computing system.
The most widely used means of communication nowadays is known as Universal Serial Bus or USB (which you will be more familiar with).
USB is a protocol of communication, connection and power supply for cables, connectors and devices such as computers and peripherals.
However a computing system is limited by how many USB ports it has, and with the number of peripherals increasing, you will require a device such as a USB Hub to extend how many ports it has.
But, sometimes one USB Hub is not enough and you might require to connect another USB Hub to it.
Lucky for you and me, connecting one USB hub into another isn’t a problem.
SInce a USB hub is essentially a USB device and uses the same protocols for communication, it can be plugged to another USB Hub.
What factors to consider when plugging one USB hub into another
While it is possible to connect a USB Hub into another, there are some factors to consider before doing so to ensure you get the most efficient connection.
Transfer speed
There are many different Transfer Speeds available for USB cables, connectors,ports and USB Hubs available.
Transfer speed is how much data is able to be transfered.
Earlier versions (USB 1.0) had transfer speeds of 1.5 Mbps (Megabits per second). This version is the lowest of the transfer speeds available for USB devices.
Below are the other cable transfer speeds (with the last one being the latest);
- USB 1.1 / Full-speed (12 Mbps)
- USB 2.0 / Hi-Speed (480 Mbps)
- USB 3.0 / Super-speed (5 Gbps)
- USB 3.1 / Super-speed (10 Gbps)
When connecting one USB hub into another you will need to make sure that they are both the same versions otherwise you will be restricted to the speed of the USB hub that is the lowest version.
For example, if you connect a USB hub which is version 1.1, to one that is version 3.1, the maximum transfer speed will be limited to version 1.1 (12Mbps).
So ensure they are both the same versions to achieve the fastest transfer speeds.
Power consumption
The next thing you want to take into account when connecting one USB hub into another is power consumption.
Power is shared amongst devices that are connected to a USB hub.
While connecting two USB hubs together won’t place much stress on the host system, you will inevitably be connecting devices that will require power and by having two USB hubs means you have more slots available.
You will have to be cautious as to the power requirements of the devices you will be using. Connecting multiple power hungry devices to both the USB hubs will place a lot of stress on the host system.
This issue arises when using Unpowered USB Hubs.
This type of USB hub does not have its own power supply and uses power supplied from the host system.
A way to combat this is to use a Powered USB Hub.
As the name suggests, these USB hubs have their own separate power supply so they aren’t stealing power from the host system.
Transfer speed consumption
The last factor to plan for is Transfer Speed Consumption.
The same way that power is shared amongst devices connected to a USB, so are their transfer speeds.
Every device requires a certain amount of transfer speed to operate at optimal conditions.
If you connect multiple devices that require high transfer speeds, the end result will be that the transfer speed will be shared amongst them thus limiting them to less than optimal speeds.
Devices such as External Hard Drives require high transfer speeds.
The only way to solve this issue is to limit how many devices that require high transfer speeds are connected to a USB hub at any given time.
Do the USB Hubs have to be the same brand in order to connect them?
No, the two USB hubs that you connect together do not have to be off the same brand. All USB hub manufacturers will use the same USB protocol. The only thing that will vary and which you will have to take into account is what version of USB hubs you are connecting together.
As you saw previously, connecting two USB hubs of different speeds will limit your transfer speed to that of the lower version.
Do the USB Hubs need to have the same number of ports to connect them?
No, the number of ports a USB hub has does not matter when you plug one into another.
You will however, have to calculate how many USB ports you need which allow you to connect two USB hubs with sufficient ports.
For example, if you already have a 4-port USB hub and require 7-ports in total, you will need to connect another 4-port USB hub (you will lose one USB port from the first USB hub as you plug the other one into it).
Advantage of plugging a USB hub into another
The biggest and most obvious advantage of plugging one USB hub into another is that you are able to extend the number of USB ports your computing system has.
This means you are not limited to how many peripherals you can connect to your computing system to interact with it.
Disadvantages of connecting a USB hub into another
There are some disadvantages to using 2 USB hubs connected together.
However, they are ways to workaround them so they do not drastically affect the overall performance of the system.
As you saw earlier, if you are using an Unpowered USB Hub, a lot of stress is placed on the host system as it has the job of supplying power to both the USB Hubs as well as all the devices connected to it.
An easy fix for this is to use a Powered USB Hub which has its own power supply which the devices can feed off.
The next issue might be a slight decrease in speed when plugging another USB Hub (while miniscule, this can add up when connecting multiple USB Hubs).
Again, remember to match the versions of the USB Hubs so you do not limit the speed to the slowest version.
Is there a better option of connecting one USB Hub into another ?
USB hubs come in a variety of sizes that have as little as 2-ports all the way up to 7-ports.
Rather than connecting two 4-port USB Hubs together to get 7 USB ports, a better option would be to just buy a 7-port USB hub.
This way you will avoid the issues of reduced speeds (however small they may be).
So, first double check to see if there is a USB hub available with the right number of ports you require.
