We all know that modern motherboards all carry a thing called PCI Express (or PCIe for short). But not everyone knows what this standard is. Nor do they know what specifications this standard has had since it was formulated until today. Or why this standard was developed and what other standard it replaces. All this is what we are going to deal with in this new article.
What is PCI Express?
PCI Express (Peripheral Component Interconnect Express) is a high-speed serial data bus. Its function is to communicate between the different hardware components of a PC. These components can have all their drivers on the motherboard. Or they can use external drivers, in the case of expansion boards.
This bus was introduced in 2003. It was developed as a replacement for the now extinct PCI bus used by motherboards up to that point.
The main difference and improvement over the old PCI bus is that the bandwidth of the bus is not shared between components. This has always been a major burden on the performance of the PCI bus. Because, with that bus, by sharing all the same bandwidth, the more performance a component had. And the more bandwidth it required to operate, the lower the performance of the components connected to it. Have a look at this article to know more about best pcie wifi card 2020
All specifications and subsequent revisions are developed by the PCI Special Interest Group (PCI-SIG). The PCI Special Interest Group consists of more than 900 companies that have dedicated part of their efforts to developing this industry standard.
Versions of the PCIe bus since its creation
Currently, 6 different versions of the PCIe bus have been developed:
- PCIe 1.0: presented in 2003, it had a data transfer capacity of 2.5 GT/s (GigaTransfers per second) and 250 MB/s for each data path.
- PCIe 2.0: presented in the year 2007, it had a double data transfer rate of 5 GT/s and 500 MB/s for each data path.
- PCIe 3.0: from the year 2010, doubled again the file transfer rates to 8 WGs/s and 984.6 MB/s per data path. This is precisely why there has never been a great difference in performance between using a graphics card for this bus and a PCIe 2.0 bus.
- PCIe 4.0: From the year 2017, it doubles the transfer rates again to 16 GT/s and 1,969 MB/s. This data bus was recently introduced on motherboards for the AMD Ryzen 3000 and Threadripper 3 processors.
- PCIe 5.0: its specification has been completed this year. And, as usual, it doubles the data of the previous specification to 32 GT/S and 3,938 MB/s.
- PCIe 6.0: its specification is not yet finalised (expected in 2021). But it will double the previous specification again, reaching 64 GT/s and 7,8777 MB/s for each data path.
A special feature of the PCIe bus is that it is a modular bus. This means that the connectors used on the motherboard do not all have the same characteristics. Depending on the number of PCI Express data paths connected to them, they may be known as x1, x4, x8 or x16.