ARCHIVED: What is bus mastering?

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Bus mastering is a bus design that allows an expansion card (or plug-in board) to access the computer's memory independently of the CPU. This allows data transfer between the peripheral and the main system memory while the CPU is being used by other devices. Bus mastering usually requires that the device have its own built-in processor so that it can operate independently of the CPU. A bus-mastering peripheral can control the bus and act as if it were its own separate computer system.

The most common bus mastering devices are IDE and SCSI hard drive controllers, video cards, and network interface cards. Bus mastering can function independently of the bus architecture, and can be ISA, EISA, VLB, PCI, AGP, USB, or FireWire.

For additional information on bus mastering, please see:

  http://www.pcguide.com/ref/mbsys/buses/func_Mastering.htm