Northbridge, Southbridge, what's the fastest way to the other side of the Chipset?
A modern CPU contains hundreds of millions of individual transistors, but they are mostly allocated to performing calculations at blinding speed and temporarily holding frequently used instructions in various memory units called caches. The processor, however, does not have much say in what input, output and control signals are fed to it and what happens to the raw data that it spews out. That is the job of the chipset which converts the raw data from the CPU into instructions that the components can comprehend, and acts as a controller for all the incoming bits flowing into the CPU. Think of the chipset as an intersection traffic cop working at the speed of light and you'll start to understand the functions of the chipset.
The chipset is divided into Northbridge and Southbridge to define their internal architecture. The functions of the chipset are divided into two separate sections: the Northbridge handles the high speed channels such as intercommunication with the video controller and the memory modules, while the Southbridge controls the slower channels such as the USB ports and the network interfaces.
Chipsets are designed to work in conjunction with specific processors and motherboards. Even within a single chipset family you will have processors which are and are not supported and vice versa. Intel's LGA 775 socket (the 775 refers to the number of pins on the CPU) is infamous for having a large number of chipsets, each of which will support some LGA 775 CPUs and not others. Therefore just picking up an LGA 775 CPU off the shelf and a motherboard with the right socket is only the beginning of the determination of the compatibility of the components. Match up a chipset with an unsupported processor and you'll be staring at a blank screen for a long time.
There are four major chipset manufacturers, Intel, Nvidia, Via and SiS. To compound the complexity, each chipset is incorporated by different motherboard manufacturers in different models. It would behoove any prospective personal computer builder to familiarize themselves with the specific characteristics of each chipset and not only the compatibility with the desired CPU, but the features and the performance characteristics it will display.
The top two Intel chipsets at this time are the X38 and the P35. These chipsets are actually very similar in features and performance. That is really not all that surprising when you consider that the previous 975X was not that great an improvement over the P965 and the 955X was really not much different than the earlier and less expensive 945P chipset. Of course, the X48 and P45 are just about to be introduced and they also pride themselves on being vast improvements over their predecessors when in fact most computer users won't be able to discern any difference. The best advice is to make sure that you get the appropriate chipset for your processor, and you can determine this information by checking the websites of your CPU manufacturer. You can make the choice as to whether the handful of zoomy features on the latest and priciest chipsets offer you any advantage whatsoever. If not, then just go with the least expensive chipset your processor will work with and you'll be just fine!