Why is the width of the bus be important? how does it effect the computer?

On the motherboard, you have the processor, ram, northbridge, southbridge, and other controllers. Your processor usually has a 64-bit wide bus, although older processors have a 32-bit wide bus. The PCI slots usually run at a clock at 33 or 66 mhz. The PCI bus is 32-bit wide and on older motherboards, the ISA bus was 8 and 16-bit wide. You usually gain performance the wider the bus. On a 64-bit processor, you can use more than 4 gb or ram, which tends to make your pc faster. I hope this helps. I have lots of personal experience with computers!