2. Common Buses and their Max Bandwidth

Common Buses Max Bandwidth
PCI 132 MB/s
PCI Express 1x 250 [500]* MB/s
PCI Express 2x 500 [1000]* MB/s
PCI Express 4x 1000 [2000]* MB/s
PCI Express 8x 2000 [4000]* MB/s>
PCI Express 16x 4000 [8000]* MB/s
PCI Express 32x 8000 [16000]* MB/s
IDE (ATA100) 100 MB/s
IDE (ATA133) 133 MB/s
SATA 150 MB/s
Gigabit Ethernet 125 MB/s
IEEE1394B[Firewire] 100 MB/s


The northbridge typically handles communications among the CPU, in some cases RAM, and PCI Express (or AGP) video cards, and the southbridge. Northbridge is directly connected to AGP video, thus providing higher transfer rates.


The southbridge is one of the two chips in the core logic chipset on a personal computer (PC) motherboard, the other being the northbridge. The southbridge typically implements the slower capabilities of the motherboard in a northbridge/southbridge chipset computer architecture. A southbridge chipset handles all of a computer's I/O functions, such as USB, audio, serial, the system BIOS, the ISA bus, the interrupt controller and the IDE channels.

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