The processor, also called the central processing unit (CPU), is the brain of your PC. It controls and directs all the functions inside your PC. The CPU is the most important component of the PC, as its what controls all the instructions between everything else. This is the reason that CPU's become more powerful. As technology allows us to squeeze more transistors onto a small chip, the faster and more instructions the cpu brain can handle. The two main manufacturers of microprocessor chips for your pc are Intel and AMD. There are other manufacturers of different types of CPU's including Arm, who make the cpu chips inside mobile phones.
Old CPU's were built in a rectangular shape that was called Dual inline package (DIP), and it had two rows of connection pins on both sides. The New processors come in Pin Grid Array (PGA) packaging, which is a square type shape, and has the connection pins on all four sides of the cpu. Some CPU use a Single Edge Contact Cartridge (SECC) design. This uses a separate printed circuit board for the same PGA-type processor. Processors are placed on the motherboard using a special socket or a slot. Each motherboard has a limited amount of compatibility with each new set of CPU processors that are designed. Normally your motherboard can handle the next 3 or 4 faster CPU's before the technology has to be adapted to be compatible with the next generations of CPU's. There is also the Staggered Pin Grid Array (SPGA) packaging which uses arrays of pins, which form a diagonal square.
Types of Technology in CPU's
As CPUs get better, new breakthroughs in technology are found. If you remember the old commercials of Pentium intel inside, you'll understand how important marketing becomes to CPU manufacturers. Every little new breakthrough in technology is marketed heavily as a performance improvement.
Hyper-threading Technology (HTT)
HTT is when your cpu can simultaneously execute multi-threading (SMT). This is used in Intel’s Pentium 4 microprocessors. The technology works by improving the performance of the CPU by providing useful work to the idle execution units and allowing multiple threads to run simultaneously. This basically means doing two important tasks at the same time. Imagine how much quicker you could get to work if you were able to eat your breakfast in the shower? This is what HTT is like. CPU's that use the hyper-threading technology appear to the operating system like you have two processors. If your operating system supports symmetrical multiprocessing (SMP), then you can take advantage of this technology by scheduling separate processes on the HTT-capable CPU.
A multicore CPU integrates two or more processors into a single CPU. The operating system treats the single multicore processor as two or more separate CPU processors. Your operating system will have to support symmetrical multiprocessing to take advantage of a multicore CPU. So if you have a blazing new PC, don't go installing windows 3.1 on it for reasons of nostalgia. Just as the hardware of your pc has changed, so has the software. Intel’s Dual Core processor is an implementation of the multicore technology that contains two independent processors in a single chip. AMD pioneered the term quadcore too, with four CPU's in the same CPU.
CPU throttling is the process of controlling the amount of time spent by the processor on each instruction it deals with. The idea behind throttling is to divide the CPU time among the various applications that you have loaded up on your PC. CPU throttling is used mainly on web servers that need to make sure that the multiple visitors to your website are prioritized evenly for them to all have a consistent viewing experience. This is actually the reason why too many visitors to a website can bring down the site.
Microcode and MMX
Microcode is a series of micro instructions that control the CPU at its most basic level. Its sort of like your subconsciousness. Microcode is designed for the fastest execution of the instructions to your pc. It is executed in the high-speed memory of the computer called the control store. MMX refers to MultiMedia Extensions, and was a special microcode developed specifically for Intel’s Pentium MMX processors. MMX microcode takes the load off executing multimedia-related instructions from the CPU and acts like a helping hand.
Everyone who plays with the inside of their PC will be familiar with the term Overclocking. It is used in CPU's and sometimes other components to increase their performance. All these components run at a certain speed, called a clockrate. This clock rate has a recommended limit, normally due to the excess heat created, which can then result in the damage of the components. An overclocker will normally install a bigger fan, or a different way like water cooling to allow the full overclocking of CPU's. Obviously this is not supported under the manufacturer warranty.
The Cache of a CPU is the high-speed memory that is used to temporary store data and instructions that are most used by the CPU. Think of the cache as your pockets. An easy and fast place to store some handy extras. The cache located within the CPU is called the Level 1 Cache (L1 Cache), there is also a level 2 cache, however that is normally located on the motherboard. The function of the cache is to provide a channel between moving instructions from the memory of the PC, back and forward to the CPU.
Voltage Regulator Module (VRM)
VRM is an electronic device that gives your CPU enough supply voltage. A VRM allows CPU's requiring different supply voltages to be used on the same motherboard. As the PC starts up, the microprocessor signals the VRM to correct the voltage supply to what it needs. The VRM then supplies a consistent correct voltage to the processor. You will find this type of technology used mostly on high performance servers, and scientific PC's Don't bother asking for the feature at your local pc world shop.
The speed of your CPU is represented by its clock frequency, and this is measured in Megahertz (MHz) or Gigahertz (GHz). A Clockrate or frequency can be misleading when speeds of the processors are compared. This is due to the fact that the amount of work a different CPU can do from one CPU chip to another. This was actually used by AMD for a period of time to make their chips sound like they were just as fast as the equivalent intel chips. In reality they were not, but AMD hadn't lied, it was just that compared to the same intel chip, they were a little slower.
32-Bit versus 64-Bit Bus
One of the more recent big pushes in CPU technology is the change from 32 bit to 64 bit processing. The number of data bits that can be transmitted at any one time, or processed in parallel is represented by the bus width, which can be 32-bit or 64-bit. Its like a highway which has 64 lanes instead of 32, which do you think helps more traffic move? The width of the data lines that connect the CPU to the memory of the computer is known as the bus width. The wider the bus the better, as more data can be processed in a given amount of time. You have to make sure that you are using a 64-bit operating system to take full advantage of this feature. Or its like doubling the motorway lanes, and yest still having the same single exit lane. There is a huge bottleneck once everyone gets to their destination.
Kit (author) from Catsville on September 20, 2011:
if you have a brain, and you've been a room with nothin for 20 years, and suddenly a door opens and you'r let out, you would need an operating system to figure things out.
Billy on August 26, 2011:
Just a question if a cpu is called the brain of the computer then why need an OS if its really really the brain im just curious about this if its true then i bet sooner there will be an artificial intellegence to be used in laptops or machine just think a metalic silicon machine or whatever called brain then what is the main function of the operating system the programs codes? Can you subtantiate it between a machine and a program ?????? :$