We are independent & ad-supported. We may earn a commission for purchases made through our links.
Advertiser Disclosure
Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.
How We Make Money
We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently of our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.

What is PCI Express?

By R. Kayne
Updated May 16, 2024
Our promise to you
EasyTechJunkie is dedicated to creating trustworthy, high-quality content that always prioritizes transparency, integrity, and inclusivity above all else. Our ensure that our content creation and review process includes rigorous fact-checking, evidence-based, and continual updates to ensure accuracy and reliability.

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

Editorial Standards

At EasyTechJunkie, we are committed to creating content that you can trust. Our editorial process is designed to ensure that every piece of content we publish is accurate, reliable, and informative.

Our team of experienced writers and editors follows a strict set of guidelines to ensure the highest quality content. We conduct thorough research, fact-check all information, and rely on credible sources to back up our claims. Our content is reviewed by subject-matter experts to ensure accuracy and clarity.

We believe in transparency and maintain editorial independence from our advertisers. Our team does not receive direct compensation from advertisers, allowing us to create unbiased content that prioritizes your interests.

Peripheral Component Interconnect (PCI) Express (PCIe) is a scalable Input/Output (I/O) serial bus technology that largely replaced earlier PCI slots on motherboards. It is a port that allows certain internal components to be installed into a computer. In 2004, PCI Express slots began appearing alongside standard slots, starting a gradual transition to the new technology. While some standard PCI slots can still be found on motherboards, many computer users prefer PCI express for graphics cards and other components.

The Purpose of PCI Express

PCIe slots are found on many motherboards, letting computer users install components into them. They allow the motherboard and other software in a computer to access and use devices connected to these slots. While PCIe has been used throughout the first decade of the 21st Century, new slots are likely to replace them at some point in the future.

Benefits of PCIe Technology

PCI Express is a point-to-point connection, which means it does not share bandwidth but communicates directly with devices via a switch that directs data flow. This allows for "hot swapping" or "hot plugging," which means cards in PCIe slots can be changed without shutting down the computer, and they consume less power than previous PCI technology. One of the most promising features of PCIe is that it is scalable, which means greater bandwidth can be achieved through adding more "lanes."

PCI Express has several additional advantages, not only to the user but to manufacturers. It can be implemented as a unifying I/O structure for desktops, servers, and workstations, and it is cheaper than PCI standard to implement at the motherboard level. This keeps costs low for the consumer. It is also designed to be compatible with earlier Operating Systems and PCI device drivers.

Types of PCIe Formats

The initial rollout of PCI Express provided three consumer options: x1, x2, and x16. These numbers represents the "lanes:" x1 has 1 lane; x2 has 2 lanes, and x16 has 16. Each lane is bi-directional and consists of 4 pins. Lanes in PCIe version 1.x had a lower delivery transfer rate, but PCIe 3.0 introduced a transfer rate of 500 megabytes per second (MBps) in each direction for a total of 1,000 MBps, or 1 gigabyte per second (GBps), per lane.

PCIe Lanes Pins MBps Purpose
x1 1 4 1 GBps Device
x2 2 8 2 GBps Device
x16 16 64 16 GBps Graphics Card

PCIe and Graphics Cards

The 16-lane (x16) slot has replaced the Accelerated Graphics Port (AGP) on many motherboards and fits a PCIe graphics card. Boards that include the x1 and x2 slots usually have them for other components, such as sound or networking cards. As computer graphics demands increase, x32 and x64 slots may become available, and future versions of PCIe might improve upon lane data rates.

Other PCI Technologies

PCI Express should not be confused with PCI eXtended (PCI-X), used in the server market. PCI-X improved on standard PCI bus to deliver a maximum bandwidth of 1GBps. PCIe has been developed for the server market as well, initially with the x4, x8 and x12 formats reserved. This far exceeds PCI-X capability.

History of PCI Technology

Intel first introduced PCI technology in the early 1990s to replace the Industry Standard Architecture (ISA) bus. Although robust enough to last over a decade, total available bandwidth of just 133 MBps, shared between slots, meant that high demand devices quickly overwhelmed computer resources. In 1997 this problem was partially alleviated by implementation of a separate AGP slot with dedicated bandwidth. However, as component manufacturers developed many high-demand devices for computers, a new architecture was required, which led to the introduction of PCI Express.

EasyTechJunkie is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
Link to Sources
Discussion Comments
By anon53811 — On Nov 24, 2009

Correlate PCIE, SATA and Desktop PC? Easy, they all run on electricity, are man made and create heat when operating.

Not the right answer? Do some research!

By anon38681 — On Jul 27, 2009

How can i get an graphics card when i don't have a PCI slot?

By sivarajesh — On May 06, 2009

Can you correlate PCIE and SATA? Do they both do the same thing or are they of different standards? Correlate them with desktop PC?

By anon6472 — On Dec 29, 2007

Yes, you can put a x4 on a x8. It won't fill in the slot completely, but it will still work. However, you can't put an 8x on a x4.

By anon409 — On Apr 24, 2007

Can I put a pci- x4 in a pci-e x8 or x16 slot?


EasyTechJunkie, in your inbox

Our latest articles, guides, and more, delivered daily.

EasyTechJunkie, in your inbox

Our latest articles, guides, and more, delivered daily.