Expansion slots on the mainboard allow connecting more devices such as graphics cards, sound cards, etc. That helps the computer to handle more work. There are many types of expansion slots, but the most popular are still PCI and PCI Express (PCIe) slots.
1. ISA slot
ISA is abbreviation for Industry Standard Architecture.
This is a slot for expansion cards such as network cards, sound cards by the old standards. The transfer rate of sending data (Bus speed) from the expansion card through this slot to the mainboard is low.
2. PCI slot (Peripheral Component Interconnect)
PCI slot is an expansion slot commonly used on mainboards. The PCI slot was developed by Intel to replace the ISA slot. Bus speed of PCI slot can be 33MHz, 66MHz, 133MHz.
The PCI slot is very recognizable on the mainboard, usually has white color with 120 pins.
3. PCI Express slot
PCI Express (PCIe) slot was introduced to replace the PCI slot in 2004. The PCIe slot was created by Intel, Dell, HP, IBM.
PCIe has many versions with increasingly higher bus speeds:
- v. 1.x: 2.5 Gb/s
- v. 2.x: 5 Gb/s
- v. 3.x: 8 Gb/s
- v. 4.x: 16 Gb/s
- v. 5.x: 32 Gb/s
PCI Express slots also have x1, x4, x8, x16 types with different number of pins. The more pins, the higher the data transfer rate.
4. AGP slot (Accelerated Graphics Port)
AGP slot is a slot for only video card. This slots are classified based on bandwidth:
- AGP 1X has a bandwidth of 266 MBps
- AGP 2X has a bandwidth of 533 MBps
- AGP 4X has a bandwidth of 1066 MBps
- AGP 8X has a bandwidth of 2133 MBps
