What are the three buses commonly used in computers? Is the interface standard for connecting hard disk and motherboard IDE interface or SCSI interface?

The device connected to the bus and the connection circuit of the bus become the bus interface.

Bus interface: The graphics card must be plugged into the motherboard to exchange data with the motherboard. Interfaces connected with the motherboard mainly include isa, e isa, vesa, pci, agp, etc. Isa and eisa bus have narrow bandwidth and slow speed, and vesa bus has poor expansion ability. These three buses have been eliminated by the market. Now common are pci and agp interfaces. Pci interface is a bus interface, which works at the system bus frequency of 1/2 or 1/3 (usually 33mhz). If image data and other data are to be processed at the same time, all data flowing through pci bus must be processed separately, so there will be data retention. When the amount of data is large, the pci bus becomes very tense. Agp interface is designed to solve this problem. It is a special display interface (that is, sound card, video card, video capture card and other cards can be inserted into the pci slot of the motherboard, but all cards except agp video card cannot be inserted into the agp slot of the motherboard). It has the characteristics of a dedicated bus, and only image data can pass through the agp port. In addition, agp uses a higher bus frequency (66mhz), which greatly improves the data transmission rate.

At present, the development trend of graphics card interface is agp interface. It should be noted that agp technology can be divided into agp 1× and agp2×. The maximum theoretical data transmission rate of the latter is twice that of the former. This year, there will be a graphics card supporting agp4× (such as nature 4), and its maximum theoretical data transmission rate will reach1056 MB/s/s ... AGP interface and pci interface can be easily distinguished. The former leads are staggered up and down, commonly known as "golden fingers", while the latter leads are generally flush up and down.

Simple understanding

The connection circuit between the device connected to the bus and the bus is called the bus interface.