POST: POST (Power-On-Self-Test) is a major part of the BIOS function. It is responsible for the detection of CPU, motherboard, memory, soft disk subsystem, display subsystem (including display cache), serial parallel interface, keyboard, CD-ROM drive, etc.
PCI bus: PCI (Peripheral Component Interconnect) is a bus structure introduced by the SIG Group. It has a data transfer rate of 132 MB / S and a strong load capacity, can be applied to a variety of hardware platforms, and is compatible with ISA, EISA bus.
SCSI: SCSI (Small Computer System Interface) It can drive at least 6 (up to 32 SCSI-3 standard expansion) external devices; and its data transfer rate can reach 40Mbps, SCSI-3 can be as high as 80Mbps.