Why Increased bandwidth can be equated into increased system performance

We've long known that to get the most out of your processor you need to get as much information into it as possible, as quickly as possible. Chipset designers have consistently addressed this by increasing Front Side Bus speeds. The problem with this is that front side bus speed increases the speed of transfer between the memory and CPU but often you've got data that's coming from other sources that needs to get to the memory or CPU like drives, network traffic, video, etc. PCI Express addresses this problem head on by making it much faster and easier for data to get around the system.