Also called the "system bus," it is the pathway between the CPU, memory and peripheral devices. In the early 1990s, when the higher-speed VL-bus and PCI bus were introduced, they were called local buses, because they ran at the then-current speed of the local bus. Since then, local buses have gone way beyond the speeds of VL-bus and PCI. See bus and PC data buses.

      Bus Speed Comparisons

      Bus type  Width     Speed   Total rate
      ISA       16 bits   8 MHz   16MB/sec
      EISA      32 bits   8 MHz   32MB/sec
      VL-bus    32 bits   25 MHz  100MB/sec
      VL-bus    32 bits   33 MHz  132MB/sec
      PCI       32 bits   33 MHz  132MB/sec
      PCI       64 bits   33 MHz  264MB/sec