1.外围组件互连(PCI)：
外围组件互连(PCI)的缩写是一种计算机总线，用于连接计算机系统中的硬件设备。常规PCI是PCI的另一个名称。 PCI被设计为并行总线，并具有分配时间量的单个总线时钟。 PCI是由Intel在1992年推出的。 PCI总线的标准宽度为32位或64位。热插拔是PCI中的可选功能。
2.扩展的外围组件互连(PCI-X)：
扩展的PCI-X或外围组件互连是与扩展卡一起提供的本地计算机总线。它是外围组件互连的扩展版本，具有更高的带宽。它由IBM，HP，Compaq于1998年推出，具有支持更高时钟速度和热插拔的功能。它是并行设计的，宽度为64位。由于其运行缓慢，后来被其他名为PCI-E的版本替代。
PCI和PCI-X之间的区别：
| S.NO | PCI | PCI-X |
|---|---|---|
| 1. | PCI is a computer bus that connects hardware devices. | PCI-X is a computer bus that connects hardware devices and has an expansion card. |
| 2. | It was introduced in the year 1992 by Intel. | It was introduced in the year 1998 by IBM, HP and Compaq. |
| 3. | Conventional PCI is another name for PCI. | Peripheral Component Interconnect eXtended is the abbreviated form of PCI-X. |
| 4. | Hot swapping feature is optional. | Hot swapping feature was made mandatory. |
| 5. | It works slower. | It works faster. |
| 6. | PCI provides a slower data rate | PCI-X provides faster data rate. |
| 7. | PCI was replaced by PCI-X. | PCI-X was replaced by PCI-E. |
| 8. | The speed of a PCI slot is upto 133MB/s. | The speed of a PCI-X slot is upto 1064MB/s. |
| 9. | It has less features. | It has more features. |
| 10. | The width of PCI is about 32 or 64 bits. | The width of PCI-X is 64 bits |