What is PCI and PCI Express?

PCI Overview
 

Developed by Intel Corporation, the Peripheral Component Interconnect standard (PCI) is an industry-standard, high-speed bus found in nearly all desktop computers. PCI slots allow you to install a wide variety of expansion cards including:

• Graphics or Video cards
• Sound cards
• Network cards
• SCSI cards
• Many other types of cards

Furthermore, PCI automatically configures cards to work properly with other PCI cards in any computer.

PCI cards come in both 32-bit and 64-bit versions, as well as both 33 MHz and 66 MHz speeds. Running at 32 bits and 33 MHz, PCI yields a throughput rate of 133 MBps.

PCI Express Overview
 

Peripheral Component Interconnect Express (PCI Express) is the next evolution of PCI that uses existing PCI programming concepts and communications standards but improves the performance to match the increased speeds of modern computers. PCI Express doubles the data transfer rates of the original PCI bus.

Note: Do not confuse PCI Express with PCI-X (PCI Extended). While similar to PCI Express in function, PCI-X is based on a different type of technology.

PCI Express supports the same types of expansion cards as PCI and was designed to be backward compatible with standard PCI cards thus allowing you to continue using any existing PCI cards. However, standard PCI cards would still perform at the regular PCI speed.

PCI Express Errors and Troubleshooting Steps
 

PCI Express errors come in two classifications: correctable and uncorrectable errors.

The difference in the classifications depends on whether they resulted in performance issues or impacted the functionality of the PCL Express interface.

• Correctable errors are handled by hardware and do not impact the functionality of the interface such as data loss.
• Uncorrectable errors:
  • Nonfatal: This does not impact the integrity of the PCI Express interface, but data or information is lost and is handled by device-specific software.
  • Fatal: Causes the PCL Express interface to be unreliable. Impacts the functionality of the interface (data and information are lost). Recovery is done by resetting the component and interface.

When you receive an uncorrectable PCI Express Error, run the SupportAssist application. This application runs a quick diagnostic and has an option to run a comprehensive diagnostic. The SupportAssist application also updates drivers and optimizes your computer.

For more information, see Dell Knowledge Base article Dell SupportAssist for PCs and Tablets Frequently Asked Questions (FAQ)