PCI slots support add-on cards to provide the ports used by mice and other devices.
Expansion slots are the interfaces used between expansion cards and the motherboard. Modern desktop computers use several types of expansion slots designed to accommodate different types of expansion cards. Desktop expansion slots often support network cards, modems, sound cards and video cards. Other less common devices include RAID controllers and add-on cards that are used to provide support for RAID hard drive configurations and convert expansion slots into additional ports for external devices.
PCI Slots
There are several types of expansion slots named after the Peripheral Component Interconnect (PCI) standard. The PCI slot was first introduced in 1992 as a 32-bit interface that accommodates most types of expansion cards. The PCI slot was later upgraded to include support for 64-bit expansion cards. Although it is an older standard, this slot is still included on many modern motherboards. The PCI slot supports most types of expansion cards, including video cards, sound cards, network cards, RAID controllers, add-on cards, modems and more.
PCI Express x1
The new generation of PCI slots are known as PCI Express slots. These slots are rated based on the number of data lanes they use to transfer information. PCI Express x1 slots are designed for expansion cards that utilize relatively low amounts of bandwidth. PCI Express x1 slots are often used for sound cards, add-on cards and other common types of expansion cards.
PCI Express x4
The PCI Express x4 slot is designed for expansion cards that require more bandwidth than the PCI Express x1 slot provides. Network cards and other communications devices sometimes use this type of slot due to its ability to transfer larger amounts of data. Dedicated PCI-E x4 slots are often left off of motherboards in favor of the more powerful x16 slot, which can operate in x4 mode. Since PCI-E x4 slots are smaller than PCI-E x16 slots, expansion cards designed for PCI-E x4 slots will not fit in the larger, more common x16 slot.
PCI Express x8
The PCI Express x8 slot is designed for high-bandwidth expansion cards that do not require the same level of bandwidth used by a video card. Network cards that support multiple Ethernet connections and multiport add-on cards and RAID cards often use this type of expansion slot.
PCI Express x16
The most common type of PCI Express slot uses 16 data lanes to provide large amounts of data bandwidth for video cards. The PCI-E x16 is the largest and fastest type of PCI Express slot available. The PCI-E x16 slot is often used in x4 and x8 mode for multiple video-card configurations on low-end motherboards that have multiple PCI-E x16 slots sharing bandwidth.
Tags: expansion cards, add-on cards, cards that, Express slot, PCI-E slots