Guide to Computer Cables
Guide to Computer Cables
Explore our guide to computer cables, from power cables to data cables such as USB, and video cables such as HDMI.
Find practical advice and discover best practice for choosing the right cables for your needs.
- Power cables:
- Data cables:
- Video cables:
- Audio cables:
- Extension cables and adapters:
1. Power cables
Standard power cable (mains side, 230 V):
IEC 320 C13:
- Description: Standard female connector that plugs into many electronic devices. For example: tower desktop computers, some older and newer generation monitors, and some larger printers.
- Use: Often found at the end of power cables for computers, monitors and other equipment.
IEC 320 C5:
- Description: Cloverleaf-shaped female connector used for laptops.
- Use: Found at the end of the power cords of laptop chargers.
IEC 320 C7:
- Description: Non-polarised female connector used on small electronic devices. Also known as a “figure-8” cable.
- Use: Commonly found on camera chargers, some televisions, printers, etc.
Laptop power cable
Laptop power supplies generally maintain a constant voltage of between 18 and 21 volts, depending on the brand and model.
Although the connectors on the output side can vary, they are often compatible with one another.
When replacing a laptop’s power supply, it is crucial to pay attention to the following points:
- Standard voltage: The usual voltage is around 19 volts, but you must check the exact value on the original power supply, as it can vary depending on the brand and model of the computer.
- Current in amps: The current, expressed in amps, must also be taken into account. Whereas older computers required more powerful power supplies, current models are more energy efficient, which means lower amperages and more compact power supplies.
- Original connector: Examining the original connector on the existing power supply is crucial. If the connector is a special, non-standard type, the new power supply must be chosen with care. You can choose a replacement power supply that comes with several types of connectors to fit several types of laptops.
This type of power supply often has a selector that sets the output voltage. Be very careful to choose the right voltage because, if you do not, the power supply can destroy your computer.
How do you identify the right power supply for your laptop?
It is quite simple. Above, you can see an illustration of a laptop power supply with its various specifications. The orange frame, i.e. 19 volts, shows the voltage supplied by the power supply. The red square, i.e. 3.42 amps, represents the electrical current that the power supply can deliver. If these parameters match and the connector fits your laptop, then the power supply will be compatible.
In short, when buying a new power supply, make sure you take into account the specific voltage, the appropriate current and the compatibility of the connector. These three criteria ensure an effective replacement that is suited to your laptop.
By clicking on the image above, you can use our affiliate link to a selection of universal power supplies available on Amazon. You do not have to use our affiliate link, but if you do, thank you, as it helps us keep our website online.
2. Data cables:
USB cable:
USB Type A:
- Description: Standard rectangular connector with a flat end.
- Use cases: Used to connect peripherals such as keyboards, mice, external hard drives and chargers.
USB Type B:
- Description: Square connector with bevelled corners.
- Use cases: Often used on older peripherals such as printers, some scanners and some audio equipment.
USB 3.0 Type A:
- Description: Often identifiable by a blue colour inside. Speeds of up to 5 Gbit/s.
- Use cases: Offers faster data transfer speeds, ideal for external hard drives and other peripherals that need high throughput.
Mini USB:
- Description: Smaller connector with a flat end.
- Use cases: Mainly used on older peripherals such as some cameras, camcorders and portable GPS units.
Micro USB:
- Description: Small, flat connector with an asymmetric shape.
- Use cases: Very common on older smartphones, tablets, some wireless earphones and other small electronic devices.
USB Type C:
- Description: Reversible connector that can be inserted either way round.
- Use cases: Increasingly used on new smartphones, laptops, tablets and audio devices worldwide. In Europe, it has been mandatory on all smartphones since 28 December 2024 under the common charger directive, which confirms its place as the universal connector.
USB Micro B:
- Description: The official name of Micro USB. Its wider USB 3.0 variant is found on many external hard drives.
- Use cases: Used on some older devices, but also found on some earphones, security cameras and other small peripherals.
Ethernet cable:
- Ethernet cables, fitted with RJ45 connectors, come in several categories. Here are the best known:
- Standard RJ45 Cat5:
- Description: Eight-contact connector used for Ethernet cables. Maximum speed of 100 Mbit/s (12.5 MB/s) over 100 metres.
- RJ45 Cat5e:
- Description: Designed to meet the Cat5e (Category 5e) specifications, offering better performance than standard RJ45. Maximum speed of 1 Gbit/s (125 MB/s) over 100 metres.
- RJ45 Cat6:
- Description: Designed to meet the Cat6 (Category 6) specifications, offering improved performance compared with Cat5e. Speed of 1 Gbit/s over 100 metres, and 10 Gbit/s (1.25 GB/s) over 55 metres at most.
- RJ45 Cat6a:
- Description: Designed to meet the Cat6a (Category 6a) specifications, offering even better performance in terms of speed and interference reduction. Speed of 10 Gbit/s (1.25 GB/s) over 100 metres.
- RJ45 Cat7:
- Description: Cat7 was designed for 10 Gbit/s over 100 metres, with a bandwidth of 600 MHz. Higher speeds have been achieved in the laboratory over short distances, but no mainstream equipment makes use of them.
- RJ45 Cat8:
- Description: Cat8 is the most modern and fastest Ethernet cable, with speeds of up to 40 Gbit/s, but over 30 metres at most, outperforming Cat7 and Cat6a. It offers a bandwidth of 2 GHz, ideal for data centres that need fast communication between switches. Although more expensive, Cat8 is a future-proof cabling solution with exceptional performance, rivalling fibre optics in environments that require high bandwidth.
Practical advice: Choose the category according to the speed you need and the distance between devices: beyond 55 metres, 10 Gbit/s requires at least Cat6a.
SATA cable
- The SATA (Serial ATA) cable is used to connect hard drives and SSDs to computer motherboards. Thanks to its rectangular locking design, it provides a stable connection and makes cable management inside the case easier. With its fast transfer rates, the SATA cable improves the performance of storage devices, playing an essential role in modern computer setups.
3. Video cables:
VGA cable:
- Description: The VGA (Video Graphics Array) cable is an analogue cable commonly used to transmit video signals between a computer and a monitor. It can be identified by its blue 15-pin connectors and is often used for resolutions up to 1080p.
DVI cable:
- Description: The DVI (Digital Visual Interface) cable is a digital cable designed to transmit high-quality video signals. It comes in three types: DVI-A (analogue), DVI-D (digital) and DVI-I (carrying both analogue and digital signals). It is used for resolutions of up to 2560×1600 pixels.
DisplayPort cable:
- Description: The DisplayPort cable is a digital standard offering superior transmission quality for audio and video. It supports high resolutions, up to 8K, and can also carry audio signals. The connectors are slim and not reversible.
HDMI cable:
- Description: The HDMI (High-Definition Multimedia Interface) cable is a versatile cable used to connect various audio and video devices, such as televisions, Blu-ray players and games consoles. It supports resolutions of up to 4K, and up to 8K and 10K with HDMI 2.1 (“Ultra High Speed” cable). It can carry both audio and video over a single cable.
USB-C cable:
- Description: The USB-C cable is designed not only for fast data transfers, but is also increasingly used to send video signals to certain compatible monitors. Its connector tells you nothing about its speed: depending on the USB standard of the cable and the device, the speed ranges from 480 Mbit/s (USB 2.0) to 40 Gbit/s (USB4), or even 80 Gbit/s (USB4 version 2.0). Video is carried using DisplayPort mode (DisplayPort Alternate Mode), if the device supports it. Frequently used to connect peripherals such as external hard drives and cameras, and now to send video signals to USB-C compatible monitors.
Cables of the past that are gradually fading away
- SCSI (Small Computer System Interface) cable: Used to connect peripherals such as hard drives and scanners.
- Parallel cable: Once used to connect printers and other peripherals, it has largely been replaced by faster interfaces.
- FireWire (IEEE 1394) cable: Used for fast data transfer, it was popular in camcorders and external hard drives, but has been replaced by more recent technologies such as USB and Thunderbolt.
- IDE (Integrated Drive Electronics) cable: Used to connect hard drives and optical drives, it has been superseded by the SATA interface for modern drives.
- S-Video cable: Used for video connections, mainly in audiovisual devices. It has been replaced by HDMI and DisplayPort connections.
- Coaxial network cable (10Base2): Used in older Ethernet networks, it has been replaced by twisted-pair Ethernet cables (such as Cat5e and Cat6).
- RS-232 (serial) cable: Used for serial communication between computers and peripherals, it has been replaced by more modern interfaces such as USB.
- PS/2 cable: Used to connect keyboards and mice to computers, it has largely been replaced by USB connections.
- 30-pin Dock cable: Used with older iPhones, iPads and iPods, this cable was replaced by the Lightning connector.
- Lightning to USB-A cable: Used to charge and sync iPhones, iPads and iPods fitted with the Lightning connector. Apple replaced it with USB-C from the iPhone 15 (2023) onwards, but it is still very common on older devices.
- MagSafe cable (for MacBook): Used to charge older MacBooks via a magnetic connection. Apple replaced it with USB-C from 2016, then reintroduced it in 2021 as MagSafe 3 on the MacBook Pro.
- Thunderbolt cable: Used for fast data transfers and to connect external monitors to Macs. Replaced by Thunderbolt 2, then by Thunderbolt 3, which uses the USB-C connector, as do its successors.
- Apple Watch cable: Used to charge Apple watches. Although still in use, it can be replaced by more modern wireless charging solutions.
4. Audio cables:
Jack cable:
- Description: The jack cable, also known as an audio jack cable, is an analogue cable used for audio transmission. It has a cylindrical plug with one or more rings, which indicate the type of signal it can carry (stereo, mono, etc.).
- Use cases: Commonly used to connect audio devices such as headphones, speakers, microphones and other audio equipment.
RCA cable:
- Description: The RCA cable is an analogue cable with RCA connectors at each end, usually red and white for the left and right audio channels. Some cables also have a yellow plug for the video signal. It is used to carry analogue audio and video signals.
- Use cases: Often used to connect audiovisual devices such as DVD players, games consoles, AV receivers and other peripherals.
Optical cable:
- Description: Also known as a TOSLINK cable, it uses light to transmit digital audio signals. The connectors contain optical fibres that carry the light signals.
- Use cases: Mainly used to connect digital audio devices such as soundbars, AV receivers and televisions to audio sources such as Blu-ray players, games consoles and other digital devices.
5. Extension cables and adapters:
Extension leads and power strips:
- Extension leads are essential devices for extending the reach of power sockets, offering a practical solution in a wide range of settings. Here are a few key points to know:
- Description: Extension leads are cables with sockets at one end and a plug at the other, which extend the distance between electronic devices and the power source. They are available in different lengths to suit specific needs.
- Use cases: Used in homes, offices, building sites and at outdoor events, extension leads make it possible to power electronic devices such as lamps, computers, power tools and other electrical equipment from a single power socket.
- Safety: It is crucial to use extension leads that comply with safety standards, with thick cables and well-insulated sockets, to avoid the risk of fire or overheating. Avoid overloading by respecting the maximum power rating shown on the extension lead.
- Types: There are different types of extension leads, including those with multiple sockets, cable reels and models designed for outdoor use with weather protection.
USB adapters:
USB adapters are versatile devices that make it easier to connect different electronic devices. Here are a few key points to understand how useful they are:
- Description: USB adapters are compact accessories used to convert or extend USB ports on a wide range of devices. They can take the form of converters, hubs or extensions, offering broader connectivity.
- Use cases: Used in many situations, USB adapters make it possible to connect peripherals such as USB flash drives, hard drives, mice, keyboards, printers and other equipment to computers, tablets, smartphones or other USB-compatible devices.
- Types: There is a wide variety of USB adapters, each suited to specific needs. Multi-port USB hubs increase the number of available ports, USB-C adapters ease the transition to this new standard, and USB converters to other interfaces (HDMI, Ethernet, etc.) provide broader connectivity.
- Compatibility: It is crucial to choose USB adapters that are compatible with the devices they will be connected to. The USB standards (USB 2.0, USB 3.x, USB4) determine the data transfer speed; USB-C is only a connector format.
HDMI to VGA adapters:
HDMI to VGA adapters are essential devices for solving compatibility problems between modern devices with HDMI ports and older equipment using VGA ports. Here are a few key things to know about these adapters:
- Description: HDMI to VGA adapters convert the digital HDMI video signal into an analogue VGA signal. They have an HDMI connector at one end and a VGA connector at the other, so you can connect devices such as laptops, games consoles or media players to older screens that only have VGA inputs.
- Use cases: These adapters are particularly useful when you need to connect a recent device, such as a laptop, to a projector, monitor or screen that only supports the VGA interface. They bridge the gap between new HDMI technology and older equipment.
- Installation: Using these adapters is generally simple. Just plug the HDMI connector into the signal source (computer, console, etc.) and the VGA connector into the destination screen. Some adapters may also need a separate audio connection, as VGA only carries the video signal.
- Resolution: It is important to note that the quality of the resolution depends on the adapter’s ability to convert the digital signal into an analogue one. Good-quality adapters can deliver sharp, clear images, while less capable models can lead to a loss of image quality.
Conclusion:
We hope this article has been an informative and useful resource to help you better understand the different types of cables and adapters. Our team has done everything possible to provide accurate and relevant information. However, it is important to note that technology evolves quickly, and updates may occur.
Despite our efforts, errors may remain. We encourage our readers to carry out their own checks and to consult additional sources if necessary. If you notice any inaccuracies or have any concerns, please do not hesitate to contact us for clarification.
IAV S.à r.l. accepts no liability for errors or for actions taken by users on the basis of the information provided in this article.
As products evolve, we recommend checking the technical specifications with the manufacturers before any purchase or use.
Thank you for your trust and for reading our article. If you have any suggestions, questions or topics you would like to see covered in the future, please do let us know.
As an Amazon Associate, we earn from qualifying purchases.
IAV S.à r.l. - depuis 2008 - iav.lu