How Does A Processor Work?

There are three main groups of functions inside the processor: fetching, storing and executing.

To start, instructions must be fetched from memory. First, the cache (a small, but very fast, amount of memory inside the processor) is checked to see if it contains this information. If it doesn't, the processor must fetch it from the memory on the motherboard.

Data is also fetched in a similar process. The data cache is checked and data to be worked on passed on to the chip's storage registers, awaiting an instruction.

Instruction execution means the instructions pass to the decoder, which breaks up any complex instructions into a series of simpler ones. These then travel on to the execution units that actually carry out the instruction. There are two types of instruction execution units: integer units and the floating point unit (FPU). Integer units can handle many instructions easily, but they are very inefficient at some type of calculation, particularly those that involve numbers with decimal points. These are passed to the floating point unit instead, which is an area of the processor that is designed exclusively to calculate complex mathematical operations.

The instructions are then sent to the processor's storage registers where any necessary data is stored. Now the instructions actually operate on the data: the clock ticks and the results are stored once more in the processor's registers. The whole process runs as a pipeline so the next instruction is right behind and ready for execution, having been fetched from the memory.

While a factory might speed up and slow down, according to the time of day and/or demands of work, the processor works at a constant pace, its speed governed by the computer's internal clock. The more ticks per second there are, the faster the instructions are executed.

There are several stages to an instruction's execution. With each clock tick, the processor moves on one step. The clocks, even those that are employed in home computers, tick millions of times a second, and are measured in Megahertz or Gigahertz (2GHz, for instance, indicates two billion ticks per second).

Modern processors can work on several instructions in parallel. This is rather like a team of cooks in a burger restaurant working on different parts of a meal at once. Instead of one person preparing all the parts of a meal in sequence, first the burger, then the chips, next the hot apple pie and finally the drink , several work at once in a parallel pipeline, making the whole meal in much less time.

Processor Physical Installation Procedure

1. Determine Socket Type: The first step is to figure out if you have a ZIF (Zero Insertion Force) socket on your motherboard. The key to this is to look for a small plastic or metal lever along one side of the socket. If you see one, it is a ZIF socket. Virtually all Pentium class or later motherboards have these, and many 486 motherboards do as well.
2. Orient Processor To Socket: The processor and socket are both square, so you have to be sure to orient the processor so that it lines up correctly to the socket. Both pieces of hardware will have a distinguishing mark in one corner to indicate where pin 1 is. On the processor, look for one of the following: a dot on the surface of the chip in one corner; a notch in one corner; a diagonal bit of gold coming from the patch on the underside of the chip; or a square-shaped gold pad where one of the corner pins connects to the underside of the chip. Typical markings on the socket are a slightly different pattern of pin holes in one corner, a "1", or a notch in the socket.
3. Open ZIF Socket: Assuming that your board has a ZIF socket, open it up. This is done by grasping the lever next to the socket, and then lifting it up and pulling it back until it is vertical, perpendicular to the motherboard. On some ZIF sockets, you will have to pull the lever out away from the socket first slightly before lifting it up. This will cause the top part of the socket to shift and thereby open the socket. On some older motherboards the lever can tend to stick and it may take a bit of pressure to get the lever to get all the way open.
4. Insert Processor Into Socket: Double-check the orientation of the processor, and then place it into the socket. Follow these instructions depending on what type of socket you have :

• ZIF Socket: The ZIF socket is appropriately named; the CPU should really drop right into the socket and no force at all should be required. If any is, you probably don't have the socket all the way open. Lightly tap the processor into place in the socket.
• Non-ZIF Socket: Older non-ZIF sockets require you to push the processor into the socket. If you do this incorrectly you can damage the CPU. The way to do it is to first put the ends of the pins into the socket. Apply light pressure all around the surface of the CPU. Then move around the surface of the processor, applying firm but even pressure over the entire surface. Go slowly; it may take a full minute or longer. Don't push too hard and make sure the pressure is even.
3. Check That Chip Is Inserted Fully: Carefully check the processor to make sure that it is fully inserted into the socket. There should be very little space between the bottom surface of the processor and the top of the socket, less than 1/16" (less than 1 mm).
4. Close ZIF Socket: Assuming that you are using a ZIF socket board, close the socket. Gently push the lever down. You may encounter some resistance while doing this, which is normal, but if you have to really lean on it then either the socket is defective or you have the processor inserted incorrectly. The lever should go all the way down and rest next to the socket, where it was before you started.