Wired Methods of Connecting Devices

## Wired connections

### USB

The Universal Serial Bus (USB) is a wired connection technique that is widely used. We commonly utilize it to connect a variety of external devices to our computer.

#### Advantages

* USB has an excellent data transfer speed. USB 3.0 can transfer 5Gbps. This would let you transfer an HD movie between an external HDD to your computer in seconds.
* You can connect multiple peripherals to a single USB port. It is technically possible to connect 127 different devices to a single USB port.
* USB provides power to the device you are connecting. This means you need not have an external mains power supply to many peripherals when they connect using USB.
* Pretty much every computer system has a USB port. Even USB 3.0 devices are backwards compatible with USB 2.0 ports (and vice versa) to ensure it is compatible with your device.

#### Disadvantages

* USB has a relatively short range. The maximum practical length of USB 3.0 is just 3 meters

### Sata

Serial ATA is a method of connecting storage devices to a computer. It has evolved over the years with the current standard being SATA III.

#### Advantages

* SATA III is an extremely fast connection type, capable of transmitting data at 6Gbps. This is even faster than USB 3.0.
* All internal storage devices will have a SATA connector. External storage devices are not very likely to have an eSATA port though.

#### Disadvantages

* A SATA cable has a shorter range than even USB 3.0. This isn’t such an issue as we usually only use SATA cables internally, however, eSATA only has a range of 2 meters.
* Unlike USB, SATA doesn’t supply power to a device so a hard drive connecting using it needs an additional power connector.

### VGA

Visual Graphics Array is a connector used for display devices such as monitors and projectors. You might recognize the familiar chunky blue connector that the VGA cable is known for and may still be used in your school or home PC.

#### Advantages

* Older technologies that you still often encounter, particularly in the workplace, will be compatible with it.
* VGA (and DVI) have locking mechanisms built in to ensure the cable remains securely connected.

#### Disadvantages

* Unlike other display connectors like DVI & HDMI, VGA transmits analogue data (as opposed to digital). This means the signal degrades easily due to things like length & analogue to digital conversion.
* VGA cannot handle the same quality resolution as the other digital methods. The latest and most modern versions can handle 1080p HD, but certainly not 4K.
* VGA cannot transfer an audio signal along with the video signal, though neither can DVI. This means you’ll require separate audio cables to connect sound.

### HDMI

HDMI is another method of connecting display devices, such as televisions, monitors and projectors, to a computer.

#### Advantages

* HDMI has an extremely high bandwidth of 18Gbps. This allows it to output 4K quality video at 60Hz. This is a very high-quality display output.
* An audio signal can be transmitted along with the video signal using HDMI. So separate audio cables are not required if your display has built-in sound.

#### Disadvantages

* It has no locking mechanism, so cables can fall out of a device accidentally.

### Ethernet Cable

This is a form of UTP/STP cable that is used to transmit data between IT systems.

#### Advantages

* It is a very reliable connection method. Unlike WIFI, it isn’t a shared medium so bandwidth isn’t split across multiple users and it is also not very susceptible to interference.
* It has a very good range compared to most other cables. It can transfer data 100 meters. This is especially good due it being able to transfer as much as 1000Mbps.
* It is extremely common in most types of computers to have an ethernet port.

#### Disadvantages

* Compared to WIFI it offers limited mobility as you need to have a physical wire running from your computer to the connection point.
* You rarely find an ethernet port in mobile devices and it is becoming less common in laptops too.
* It cannot transfer data over very long distances, and so, is of no use to very large networks.

### Fiber optic

Fiber optic cable is a connection method where data is transferred through the use of pulses of light. The cable itself is made of tiny reflective glass or plastic fibers. The light pulses bounce off the reflective surface to transmit down the cable.

#### Advantages

* Exceptionally good data transfer speeds are probably it’s biggest benefit.  Around 100Gbps is generally what we identify as the max speed of fibre optic cable, though much faster is theoretically possible.
* It also has an excellent range. Transferring data over a distance of 100km is possible with fibre optic cables.
* It is a very secure connection method as it is not susceptible to interference or generating noise and cannot be tapped to intercept data.

#### Disadvantages

* It is very expensive. Technically the cable itself on a per distance basis isn’t expensive but the extra equipment required to run the network makes it much more costly.