What is a PCI Express (PCIe) Slot?

By Huntsends

PCI Express stands for Peripheral Component Interconnect Express. This is a type of connection that has become a standard used in virtually all internal components of a computer. It has been developed as a successor to the original PCI and its main advantage over previous versions is that it no longer relies on a serial bus. Instead, it uses a point-to-point access bus.

You will hear about PCI Express when you refer to compatible expansion slots on the motherboard. It also refers to the current types of expansion cards. Do not worry if it's a bit confusing at first. We will try to understand how PCI Express has become such an important internal interface since much of today's computer motherboards are built exclusively with PCI Express slots.

The interface plays a key role in the interaction between the devices and the motherboard. It allows broadband communication between them or any other material. PCI Express devices slip into the corresponding slot on the motherboard.

Although this is primarily an internal interface, there is also an external PCI Express version. The devices that use this interface are external, so special cables are required to make the connections. There is usually a dedicated external PCIe port for connecting compatible devices to the computer.

Many cards use very powerful interface. Video cards, in particular, have taken advantage of PCI Express's features to meet the demand for more realistic graphics and better video editing tools. It's safe to say that the video card is the most common type of PCI Express card, but it's not the only one.

Other devices may also benefit from superior connections to the motherboard. Some notable examples are the CPU and RAM which are more and more created to support PCI Express instead of PCI. Sound cards and network interface cards can be found to rely on this fast interface although it is mainly reserved for these high-end components.

Some cards that really benefited from the breakthrough PCIe are those of hard disk controllers. A good example is a high-speed SSD that can improve write and read performance through a PCI Express connection. There are some hard disk controllers that use this interface and come with a built-in SSD, something that could be considered the next step in the way that storage devices have participated in a computer.

As PCI Express has been gaining popularity due to its increased performance as stated in saim deals the BrosTrend 1200Mbps long range is one of the fastest and cheapest PCI card ever, virtually all types of internal expansion cards have received upgrades for PCI Express support over the old PCI. Bluetooth or USB expansion cards are worth mentioning.

There are so many PCI Express formats that you can be quickly overwhelmed if you are trying to determine if a specific connection can be established without incompatibility. It is not always clear when looking for a new video card how to make the optimal choice in terms of PCI Express technologies.

A key aspect of PCI Express to understand the operation of this interface is to distinguish between the part that refers to the physical size and the part that expresses the technological version.

Let's look at the different sizes of PCI Express and what each one tries to define.

  • PCI Express x1 - 25 mm
  • PCI Express x4 - 39 mm
  • PCI Express x8 - 56 mm
  • PCI Express x16 - 89 mm

The number after 'x' indicates the size of the card or slot. The larger size of the PCI Express also has a larger number of pins and vice versa, as shown below.

  • PCI Express x1 - 18 pins
  • PCI Express x4 - 32 pin
  • PCI Express x8 - 49 pin
  • PCI Express x16 - 82 pins

A key point to understand here is that you will always have some space in the PCI Express card or in the slot at the length of pin 11. This means that there is a certain level of flexibility when it s is to use cards of a size different from that accepted by the slot.

The simple rule is that a PCI Express card can fit into any slot as long as it is equal or larger. Basically, a PCIe x1 card should fit in larger slots like PCI Express x4, x8, or x16. The problem appears when you try to add, for example, a large PCIe x8 card in PCIe x1 or x4 slots. It does not work like that. It will only be compatible with PCIe x8 or x16 slots.

This is only an empirical rule. There may be exceptions when some cards fit into open slots. These are PCI Express slots that do not have a plug at the end. Larger and better PCIe cards are better, so if you're trying to make comparisons, you should keep that in mind. Of course, this is only assuming that you compare cards or slots that work with the same version of PCI Express.

If you look closely, you will notice that there is a number that follows the PCIe label on any product that supports it. This is the version number. There are differences between versions, but the good news is that you will not have compatibility issues between versions.

The latest PCIe version is 4.0 and was introduced in 2017. The older versions are 1.0, 2.0 and 3.0. The main difference between the two lies in the performance of the links. Newer versions have better transfer rates and higher throughput.

Choosing the latest PCI Express update is definitely recommended if you want to maximize the potential of your connected hardware. In addition to raw performance, the new releases also feature additional features, bug fixes, and more efficient power management.

This section is designed for those who want the best PCI Express compatibility. It goes beyond the idea that if he adapts physically, he works and that's enough. It's interesting to see what can be done to make sure you really get the potential of a better PCI Express interface.

To give you a simple example to understand, let's take a PCIe 3.0 x16 video card. To get the most out of it, your motherboard must be up to the mark in terms of performance. It needs a free x16 PCIe slot, but that's not enough. It will also require support for PCI Express 3.0 for optimal compatibility. With a lower version, you can expect reduced bandwidth performance, so try to avoid that.

If you are unsure of the current version supported by your motherboard, you can always consult the documentation on the manufacturer's website. It should be noted that, at least in the example of the PCI 3.0 x 16 video cards, there is no need to worry too much about compatibility if your motherboard is fairly new. Almost all post-2013 motherboards should support the PCI Express 3.0 version.

What does the PCI Express reserve for the future? It seems that the interface has gained popularity in recent times and the constant development focuses on improving the technology. The next PCI Express version, PCIe 5.0, is expected to arrive in 2019 with a bandwidth twice as fast as the PCI Express 4.0 version, which is currently the fastest.

Although the technology industry is exploring alternative interfaces, the main problem it faces is the need for major material changes. This does not mean that PCI Express will be there for indefinitely. It's just that from its looks, it's the best interface available and the only one that is actively getting serious updates. Performance requirements will continue to increase as the demand for a faster interface increases, particularly in the development of computer video games.