All About Peripheral Component Interconnect Express

To many people, a PC is just a simple machine that is used to retrieve and input data. This is however not the case as a PC is more than just a monitor and keyboard.

A PC usually is a mixture of a number of hardware connections. Many people do not understand the technicalities that PCs come with.

One of such connections is an expansion bus standard which basically is a movement bus which helps in the transfer of data between the computer`s internal hardware and the peripheral devices.

It is actually more like a collection of wires that eases the expansion of computers. A good example of internal hardware of a PC is a motherboard.

So, What Is PCI Express?

Peripheral Component Interconnect Express (PCIe) is a creation of Intel, HP, Dell and IBM that was created in 2004. Its launch saw the famous AGP, PCI and PCI-x that had been in use been superseded.

PCIe is basically a serial computer bus expansion that is characterized by very high speeds. It currently ranks as the most common expansion slot that comes with modern PCs.

PCIe introduction came with a number of improvements that give it an edge over the older expansion bus standards.

These improvements are credited to its prominence and they include:

  • The performance in regards to the scaling of the bus devices is higher.
  • Its ability to detect and report error is greater compared to other expansion bus standards.
  • The pin count of the input /output is lower compared to its counterparts.
  • It has a native hot plug functionality meaning that one can add a component to the system without interrupting the system. The need for restarting is not necessary.
  • It uses serial communication method whereby only one bit is transferred on the data path per clock cycle.

#Peripheral Devices That Use PCI Express Slot

  • Graphics Cards: This is the computer hardware that converts data to images that are displayed on the monitor.
  • Internal WiFi Cards: which are used to transmit internet network.
  • Ethernet Cards: This is basically a communication technology that offers data speeds to a maximum of ten bits per second.
  • Hard Drives By Raid Controller: A hard drive basically is a storage device that stores information on the computer permanently, including all data deleted fully out of the recycle bin.
  • Solid State Drives: Data here is stored on solid state flash memory.
  • And, a lot more.

#Speed Difference of PCI Express Slots

Usually, PCIe is organized into lanes which help in differentiating the various types of PCIe slots.

PCI Express 4.0

  • This is considered to be the future of bus expansion. Initially, its launch was expected in early 2017, though there seems to have been a delay. It is now considered a 2018 project.
  • It is expected to improve an already good and efficient bus expansion. Among the features it is expected to come with include: Speeds are expected to be better than the current 3.0 model.
  • Just like with all others, it is expected to be backward compatible, meaning that older version devices.
  • It is expected to introduce high interconnect performance bandwidth of 16 GTPS.
  • Better power saving modes such as the use of lower power during idle mode.

PCI Express 3.0

  • Recently, a number of chip vendors have introduced architecture improvements such as silicon on PCIe 3.0.
  • The speed of PCIe 3.0 falls within the same range as that of PCIe 2.0. Its communication speed, however, ranks highly and cannot be compared to that of PCIe 2.0.
  • There have been a number of protocol management improvements from those of PCIe 2.0.
  • The transfer rate per lane goes to a maximum of 1 Gbps.
  • All models are compatible with PCIe 3.0 in regards to video cards.
  • It is mostly supported by the CPU rather than chipsets like it is in PCIe 2.0.
  • FX processors, however, do not support PCIe 3.0.
  • It is mostly supported by Intel CPU`s.

PCI Express 2.0

  • The availability of PCIe 2.0 was officially launched in January 2007.
  • The transfer rate is higher than that of PCIe 1.0, it actually doubles it.
  • There is a higher per rate throughput in PCIe 2.0 compared to that of PCIe 1.0 but a higher one compared to PCIe 3.0.
  • It has a similar speed to that of PCIe 3.0 but the results achieved are not as much.
  • It is supported by chipsets.
  • The throughput per lane is 500 MB/seconds.

PCI Express 1.0

  • PCIe 1.0 was introduced in the year 2003.
  • The transfer rate at PCIe 1.0 stands at 2.5 Giga-transfers per second.
  • There is a per-lane data rate of 250 MB/second.
  • PCIe 1.0 uses 8b/10b encoding scheme.

It is possible to send and receive 250 MB/ second at the same time which many translate as 500 MB/ sec.

This is however not right because sending and receiving cannot happen simultaneously.

#Types of PCI Express Slots

Every motherboard in most recent PCs come with at least one slot in it. Many modern PCs in addition to standard PCI’s come with PCIe slots.

PCIe slots are more effective and efficient, for instance, they provide up to 30 times the throughput of the PCI bus.

And you know, the length of the slot determines the amount of data that can be moved.

PCI Express x1This slot came to replace the PCI ports. In this slot, data is moved within the motherboard. During its designing, the idea was to use the slot for video cards which has in the recent past proved to be a little problematic.

Usually, there is not much function for this kind of slot rather than use for network cards and SATA cards. Network cards are such as WiFi and Ethernet, which can be wireless or wired. SATA Cards are hardware interfaces that are used to connect motherboards and the storage drives.

PCI Express x4This slot has got Four lanes and provides better performance than the PCIe *1 slots.

PCI Express x8This slot has got eight lanes and provides better performance than the PCIe *4 slots.

PCI Express x16 – This slot has got 16 lanes and only use is video cards. This is because other devices can use other PCIe types, unlike video which requires very high potential bandwidths.

When it comes to PCIe, higher bandwidth does not always necessarily mean higher or better performance. The bandwidth for each slot type is subject to issues such as the overhead limitation of the software.

The only thing that bandwidth really affects is the data transfer speed, but does not affect the speed of the computer functionality.

“And that’s all for now, thanks for sticking with the article, and you know it will always good to let me know about the tutorial, in the comments down below.” 🙂


  1. for Christ sakes, when will we finally see PCIe 4.0 ??? So tired of waiting for stuff that has been delayed for so long.


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