Components on a motherboard.
There are a number of components on a motherboard apart from memory and CPU, that make up the essential glue between each of the main components. They don't receive much recognition, so here is some information about them.
The shipset is made up from a collection of semiconductor chips that allow the connectivity and information passing between the expension cards, memory, and the other important components on the main board. There are a variety of chipset makers, and they are refered to as the OEM, or Original Equipment Manufacturer. As technoligy imporves so do the features available on these chipsets. An example of this is that most motherboard chipsets now have onboard sound and video. Years ago when motherboards first started out this was inconcevable. However, most of the time they come as standard on a pc. Ther are two different types of Chipsets, they are Northbridge and Southbridge.
Northbridge isn't a motherboard brand name, it is a technique of allowing the communication between high speed peripherals, including the memory, the PCI expansion bus, the graphics card AGP slot, and the level 2 CPU cache. Nortbridge is when the performance of the pc itself, depends on the capabilities of this chipset. If you buy your own motherboard make sure that you get the best northbridge chipset that you can, otherwise your other components are just left under performing.
The southbridge chipset controls the communication between all the pc's onboard input and output functions such as the onboard usb, firewire, ps2, audio, Lan ports and ide. The southbridge chipset is controlled by the northbridge chipset.
The bios of a PC is the software that is stored on a single chip that first starts getting your pc going once you turn the pc on. Its like your pc's own morning alarm clock. is low-level software stored on a semiconductor chip, which is called the BIOS The bios tells your chipsets, and processeor how to start communicating, and how to do it with the operating system installed on the PC.
Part of its job is to detect the hardware that is plugged in and look for what comes next once the hardware is detected. For example is an operating system like windows 7 installed? If you look inside the pc at the motherboard, you can usually see the bios chip marked specifically. There is a number of manufacturers of the bios chip including, AMI, Phoenix/Award, and Winbond. You will normally see their logos or names flashing up on the screen a second or so after you turn the pc on. There is also another important chip that helps the bios, which is the cmos chip. This stores the actual settings of the bios, and has its settings kept alive by the use of a small cmos battery.
This is what is happening when your pc might flash up that the date is wrong. Its actually the cmos battery running low, and losing the date settings. This is starting to be fazed out though, in favour of re-writable chips. Normally a chip has the instructions embedded into it, and they can't be changed, however semiconductor technoligy has moved on far beyond that now were the settings can be changed, and they are still stored in this solid state.
External cache memory
A pc uses External cache memory to help improve the performance of the CPU. The cache memory is like space to hold some thoughts or instructions that the pc's CPU wants to put to the side temporarly, and think about later. There are 2 types of cache. A CPU usually has its own cache inbuilt, and that is called level 1 cache. This can be accessed the fastest. Compared to the motherboards level 2 cache. The reason is that the level 2 cache runs at the speed of the system bus on the motherboard, were as the level 1 cache runs at the speed of the CPU, which is much faster.