Ports in Your Computer | Laptop EXPLAINED!

Current ports:

USB Type-A (Universal Serial Bus):

The USB port is today the best-known connector. It is standard for exchanging data and for connecting peripherals, such as USB keys, printers, external hard drives, and many others. USB has the advantage of being “plug & play”, that is to say, that as soon as the peripheral is connected, communication is established automatically (including for the installation of driver/driver if necessary) between the device and the computer.

Over the years, USB has evolved to offer better data rates.

– USB 1.1 (commonly called USB Full Speed) offers a maximum speed of 12 Mbit / s. Today it is abandoned.

– USB 2.0 (High Speed) theoretical speed of 480 Mbit / s, or about 40 MB / s in practice. It is sometimes still present on some laptops in addition to faster ports.

– USB 3.1 gen 1 (formerly known as USB 3.0) has now become the standard and is therefore present on almost all portable PCs on the market. This new standard supports a maximum speed of 5 Gbit / s, which is a practical speed of around 300 MB / s.

– USB 3.1 gen 2 takes advantage of a higher bandwidth allowing a theoretical maximum speed of 10 Gbit / s, or about 1 GB / s in practice. The USB Type-A 3.1 gen2 ports are mainly found on gaming laptops.

– USB 3.2 is the new standard in the making. The speed is again doubled, 20 Gbit / s. No laptop PC currently offers this port (November 2019).

USB Type A 3.1 Gen2 10 Gb / s port

Apart from the datasheets of each laptop, it is often impossible to know which standard is supported by a USB Type-A port. Some manufacturers sometimes affix a “10” next to the port.

Whatever the standard of the USB ports on your computers, they are always backward compatible. This means that you can plug a USB 2.0 hard drive into a USB 3.0 port. Simply, the speed of the latter will remain “blocked” on the lowest standard and will therefore not benefit from higher flows. Similarly, an external 3.1 gen 3 SSD can be used on a computer equipped with a USB 3.1 gen 1 or even USB 2.0 port. Again, the speeds will be limited, no longer because of the peripherals as before but because of this time of the USB port of the computer.

USB Type C (or USB-C):

Since 2015, a new type of USB port has appeared on computers. This is USB Type C also called USB-C. The latter takes the standards of USB 3.x but has a different connector. More compact and above all, without polarisation. It can therefore be used in any direction. No more hesitation and multiple reversals at the time of connection!

The USB-C port is struggling to establish itself even if for 2 years, its presence has increased. Most laptops today have at least one USB Type C port. However, and this is where things get complicated, a USB-C port can hide several features :

– be used for data transfers according to the same standards as those of USB Type A mentioned above. This is generally the case for entry-level and mid-range models.

– transfer data but also serve as a power cable (up to 100W). This is often the case on high-end ultrabooks. Please note, this is not because your computer has a USB-C port that supports charging via USB-C.

– in addition to the two previous uses, the USB-C port can also carry a video signal. It can then replace an HDMI or (mini) DisplayPort via a suitable cable.

Thunderbolt 3:

The Thunderbolt 3 takes the form of a USB type C port but offers a theoretical maximum speed even higher at 40 Gbit / s while offering the possibility of chaining the peripherals between them thus opening up an infinite number of possibilities. It is also the port used to connect an external graphics card via an eGPU box.

Laptops with a Thunderbolt 3 port are still rare today in 2019. They are generally high-end laptops sold at more than $ 1,500, as some gaming laptops but also and especially ultrabooks like Apple’s Macbook Pro, Dell XPS or HP Specter.

The trend seems to be improving but some manufacturers like to maintain the confusion by using a lightning bolt, the symbol to materialize a Thunderbolt 3 port, to signal a USB-C port capable of recharging a USB device when the computer is turned off. The flash can also be found on USB-C ports that can be used for AC power.

USB-C / Thunderbolt 3 Adapter and Hub

As we mentioned, some laptops only offer USB-C or Thunderbolt 3 ports as connectors. For many, it is a brake on the purchase since the traditional USB-A and HDMI ports are then absent. USB-C to USB-A adapterWhat disoriented more than one … However, and even if this type of situation may appear as a disadvantage at first glance, in practice, it is not insurmountable by agreeing to adapt your habits. So, to occasionally connect a device with a “classic” USB port, you just have to buy (for around $ 8 ) a small USB-C to USB-A adapter that will remain permanently in your bag for always have on hand. For HDMI,(around 10 $) or more simply HDMI to USB-C cables(around 15$.

If you need more connectivity, the solution is to opt for a ” USB-C hub ” (sometimes provided at the time of purchase). The price is higher this time, with a starting price of around 20 $ but you will then benefit from one (or 2) USB-A port (s), an HDMI port or even an RJ-45 port. and / or VGA.

You will also be able to opt for more complete models with more ports and / or more “advanced” with, for example, a USB-C port compatible with Power Delivery, ie capable of supporting the mains supply. You can also take advantage of a 4K / UHD compatible HDMI port. Attention if this point is important for you, be sure to check that the HDMI port supports 4K screens at 60 Hz. A rare characteristic present only on the most expensive hubs, the others being satisfied with a 30 Hz output. For example, we recommend the Startech DKT30CHCPD, which offers a clever cable storage system as a bonus. Count around $100 for this type of high-end hub.

A price that may seem high but you quickly get a taste for connecting your screen, hard drive, network cable while powering your computer (be careful if you need more than 45W, compatible hubs are very rare) simply by plugging in a cable when you get to the office.

USB-C / Thunderbolt 3 docking station

In the same vein, but if you need more ports available, the solution is to opt for a docking station . The concept is not new, but in the past, docking stations used proprietary ports compatible, at best, with a single brand. The generalization of USB-C has made it possible to standardize the market. Computer brands like Dell, HP and Lenovo still offer their own USB-C / Thunderbolt 3 docking stations, but nothing prevents you from using them with a laptop from another brand.

In addition to the number of ports, when choosing, there are several things to keep in mind. The first is not to opt for a Thunderbolt 3 station if your computer does not have this connection. Conversely, a USB-C station can work with a laptop with Thunderbolt 3 ports. Simply, you will not take advantage of the full potential of the TB3. The main limit will be to look for the definition and the refresh rate of the screens connected to the station. A USB-C model can only connect a single UHD / 4K screen at 60 Hz or two Full HD / 1440p screens.

If you have multiple displays to connect simultaneously, only one Thunderbolt 3 station will do. And again, check the specifications with the purchase, many TB3 stations only offer 60 Hz with one screen. If you want to connect two UHD screens at 60 Hz, you will have to opt for the Startech Station TB3DOCK2DPPU or the Belkin Thunderbolt 3 Dock Pro. Count around 350 $. To date, these are the only two models to offer this dual 60 Hz support to our knowledge.


Finally, the last element to take into account, the power delivered by the USB-C / Thunderbolt 3 port. High-end stations are generally able to offer 65W or 85W. If your model requires more power, like the last Razer Blade 13 with GTX 1650, with less power the battery will recharge more slowly and especially will discharge when the system is used at full speed. It is then enough to reconnect in addition to its original power supply in parallel to resolve this “problem”. To be taken into account despite everything at the time of purchase.

HDMI (High-Definition Multimedia Interface):

HDMI has established itself in recent years as THE video port, capable of transmitting fully digital audio and video streams while allowing the management of DRM (Digital Rights Management) used for the broadcast of high definition streams (Blu-Ray or HD). DVD).

Today, laptops with an HDMI port support at least the HDM1 1.4 standard. The latter notably authorize connection to UHD / 4K screens or televisions at 30 Hz maximum. To take advantage of Very High Definition at 60 Hz, you will need a laptop PC with a minimum HDMI 2.0 port. The HMDI 2.1, still very rare, brings support for 4K at 120 Hz (and 8K).

Mini-DisplayPort / DisplayPort:

Alternative to HDMI, the mini-DisplayPort tends to disappear in favor of USB-C. Ditto for the larger DisplayPort and therefore even rarer. These ports are sometimes offered on gaming laptops. They are guaranteed to be able to connect an external 4K / UHD screen with a refresh rate of 60 images per second.

Ethernet (RJ45):

The Ethernet port is also commonly referred to as the “network port”. It makes it possible to connect the computers between them in order to exchange data but also to have remote access to a computer. It is also used to access the Internet via your modem or your “box”. It offers the advantage of offering better flow rates while being more stable. The Ethernet port is mainly found on gaming laptops today. It is still possible to use a USB to RJ-45 adapter if necessary.

3.5 mm headphone / microphone jack:

As the name suggests, this port allows you to connect headphones and / or a microphone. Sometimes separate, the sound output and the microphone input today tend to be grouped together on a single port.

(Micro) SD card reader:

Ideal for emptying the memory card of your camera, GoPro or smartphone, the SD card reader is starting to become more rare on new laptops. Some models sometimes include a micro-SD reader. Whatever the format, the integrated readers are certainly practical but their bit rates are limited to the UHS-I standard, ie in practice around 90 MB / s. The Microsoft Surface Book 2 and the Gigabyte Aero 15 are the only ones to have a UHS-II SD reader capable of mounting up to 300 MB / s with compatible cards.

Kensington anti-theft clip:

It is not a port itself but it can often be confused with USB-C or even mini-DisplayPort. The Kensington clip is used to fix a steel cable that will itself be attached to a fixed point thus offering security against theft.

The ports that have disappeared

Windows XP old / old laptop

VGA (Video Graphics Array):

It is an analog interface for connecting a monitor to a graphics card. Commonly used this 15-pin D-sub connector was gradually supplanted by the DVI and then the HMDI today. No more recent laptops are equipped with it. You should therefore opt for an adapter if you cannot do without this video port.

DVI (Digital Visual Interface):

As for the VGA, this connection also makes it possible to connect a graphics card and a monitor but this time through a digital interface. DVI has gradually imposed itself with the arrival of LCD screens allowing a completely digital link and thus avoiding analog / digital conversions causing quality losses. It is now replaced by HDMI and has therefore also disappeared from laptops since 2014.


An alternative to VGA, more compact but still analog. S-Video outputs are no longer used.

Firewire (IEEE 1394):

Firewire was the competing standard of USB but it did not have the expected success despite the advantages it presented. There were two firewire standards, the firewire 400 and the 800, offering respectively a theoretical speed of 400 and 800 Mbit / s. The firewire 400 was the most common. There were 6-pin cables that could power the peripherals and the 4-pin format that didn’t allow them to be powered. The firewire 800 had 9-pin connectors. However, it was possible to connect them to a firewire 400 socket using a 9-pin to 6-pin cable.

eSATA (external SATA):

ESATA is a type of connector which aimed to compete with USB 1.0 to connect external devices (external hard disks, burners, etc.) while benefiting from the advantages of SATA, namely a theoretical speed of 150 MB / s and the possibility of connect the peripherals “hot”; that is, without the need to reboot the system. The eSATA remained confidential and was quickly supplanted by USB 2 and then USB 3.


The port formerly used to connect a PC to a PSTN modem in order to be able to connect to the Internet. The abandonment of 56k to the profile of ADSL then of fiber relegated it to the museum and with it its “melody” so characteristic at the time of connection … It is still used to connect your “ADSL box” to your telephone line.

PS / 2:

Previously, they were used to connect mouse & keyboard. They were replaced by USB then Bluetooth.



It is a format that allows the addition of additional modules (such as USB ports, card readers, etc.) in a space provided for this purpose. There were two types of ExpressCard, 34 and 54, which actually corresponded to their respective widths of 34 and 54 mm.



The ancestor of the ExpressCard, the PCMCIA was also used for adding peripherals (network card, card reader, adding firewire port, etc.) in a space provided for this purpose.

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