PCI Slot
One of the most important parts of the motherboard is the PCI slot. The Peripheral Component Interconnect slot, it is a computer bus that is used to attach various hardware devices inside computers, both in desktops and laptops. First launched in 1993, the PCI slot has served to be the most conventional hardware component connection slot and has replaced previous standard bus types, such as the ISA and VESA local bus.
History of the PCI Slot
The development of the PCI slot took place during the early 1990s, alongside the processing of PCI-based devices by Intel. Intel used PCI to revolutionize connection technologies for hardware devices so as to promote a uniform structure and faster processing speed. PCI slots were used on second-generation Pentium PCs, and by 1996, it has replaced the VESA Local Bus on other 486 computers. Eventually, PCI has also been used as a replacement for the EISA bus; the trend for PCI has continued up to the present time.
During the mid-2000s, the PCI slot has found an upgraded competitor, the PCI Express. However, the standard PCI slot is still used even on new generation computers due to its compatibility with almost all types of hardware devices.
Specifications
The common specifications of PCI slots in normal PCs are:
- 33.33 MHz clock with synchronous transfers
- Peak transfer rate of 133 MB/s
- 32-bit bus width
- 32bit I/O port space
- 32- or 64-bit memory address space (4 gigabytes or 16 exabytes)
- 256-byte configuration space
- Reflected wave switching 5-volt signaling
PCI cards have one or two key notches based on their signaling voltage. These cards require 3.3 volts and have a notch of 56.21 mm from the front side of the card in which external connectors are found. PCI cards that require 5 volts meanwhile have a notch of 104.47 mm.
Uses of the PCI Slot
The main use of the slot is to expand the attachment of hardware devices on a computer. It is used to accommodate internal and external modems, network adapters, sound cards, video graphics cards, etc. To those who want to boost up their computer specifications, then they should determine the capacity of their PCI slots and see how many hardware devices are allowed for connection.
Not all computers have a PCI express slot present, although most of the PCs of today’s generation have made it a point to add a PCI slot on their boards. However, in case there is none present, or if there is a need for replacement, then owners may install a new PCI card on the motherboard to provide new slots.
Conventional PCI is slower than its successor, PCI Express. While both serve the same purpose, they are completely different in terms of form and structure. The PCI Express can accommodate almost the same devices in PCI slots as long as they are compatible, but these days the PCI Express slots are used for video graphics cards and sound cards. Gamers also rely on the PCI Express to improve processor speed and graphics display for high definition games.