Sections Offered In This Course...

The Basics Along with the motherboard, the Processor, also known as the CPU (Central Processing Unit) constitute the most important components of any computer. The processor is anecdotally refered to as the "brain" of your PC, and that's quite true. Like a human brain is involved in every person's activity, your computer's processor is involved in every operation that the system performs.

CPUs And Motherboards
As stated in the previous section, your motherboard must support your CPU. Whether you are replacing an older processor or starting from scratch and purchasing a new motherboard and CPU, here are some important considerations...

Compatibility With Chip Types. The first and most glaring compatibility issue is the CPU manufacturer type. All motherboards support either Intel processors or AMD processors, not both. Although both manufacturers build their chips using the same x86 standard, they are NOT compatible with the same motherboards.

NOTE: Be sure to select a motherboard that matches the manufacturer of your new CPU.

Slot Or Socket? All motherboards have a a specific type of slot or socket, into which the CPU is installed. Earlier we told you that all processors are encased in a connector package. These connection packages are designed to fit into either a slot or socket. Obviously, a connection package that is designed for a slot will not fit into a socket, and vice versa. Intel and AMD have alternated between slot and socket designs, in an attempt to improve connection integrity and to make them easier to install. However, recently the socket configuration has become the popular format.


As illustrated here, the Socket connection package format has a series of pins which are inserted into the socket on the motherboard. Today, Intel manufacturers Pentium III CPUs and Celeron CPUs utilize the Socket 370 motherboard standard for many of their popular processor speeds. This format is sometimes referred to as FC-PGA (Flip-Chip, Pin Grid Array). They may also be called PGA370 or FC-370.

The AMD Athlon and Duron processors utilize the Socket A formatted motherboards.

Voltage Compatibility. You must determine whether your new or existing motherboard is able to support your CPU's power rating, or "core voltage." If your new CPU core voltage is too high, it will create excess heat that your motherboard cannot absorb (motherboards are designed with cooling features) and you may seriously damage the motherboard. On the other hand, if your new CPU's voltage is too low, they will not support some motherboards. For example, many older Socket 370 motherboards designed for slower-speed Pentium III and Celeron processors (with core voltage of 2 volts), will not support the higher-speed Pentium III and Celerons (with core voltage or 1,6 volts).

Be sure to check voltage compatibility. It is one of the leading causes of motherboard failure and damage.

CPU Speed (Clock Speed). A processor's title, Intel Pentium III 800MHz, for example, includes the speed---800MHz. This is actually the system's "clock speed," or the backside bus speed. You'll notice that this speed is measured in Megahertz, which is millions of electronic pulses per second) or Gigahertz, which is 1,000 Megahertz. Each time there is a clock pulse, the microprocessor completes a single task.

Clock speed is just one of the indicators of overall performance. For example, an Intel Pentium III 700MHz processor is a faster processor than the Intel Celeron 700MHz, despite the fact that they both run at a clock speed of 700MHz. The Pentium III chip design includes a number of additional technical designs that improve its performance.

The same is tru of an AMD Athlon vs. an AMD Duron. The Athlon design includes speed enhancements not found in the Duron.

In summary, you may want to select a Pentium III 600MHz processor over a Celeron 700MHz in certain cases; the Pentium III would perform better in graphics-intensive work.

System Bus Speed. System bus is also called Front Side Bus (FSB). It is the "bus" over which data moves between your CPU and your system memory. This makes it a critical conduit and a major contributor to system performance. When selecting a CPU, you willl see two speeds listed----Intel Pentium III 700/133MHz. In this example, the 700 refers to the CPU's clock speed, and the 133 refers to the system bus speed.

Floating Point Calculations. Also refered to as FPU, this denotes your CPU's ability to handle complex games and 3D manipulation. While FPU is not as important for applications such as word processing and speadsheets or Internet surfing, it will dramatically increase the performance for graphics-intensive applications. If you work with graphics, check to see if the CPU you are considering supports FPU.

Memory Cache. Memory cache is a small amout of high-speed memory that is located near the processor and is set aside for frequently used operations. It is based on the fact that most of the instructions you give your software are the same, so the cache stores these instructions for fast access. Memory cache is faster for your system than having to access its main memory, so it speeds your work. There are different forms of Memory cache, named for their location (distance from the processor).

L1 Cache or Level 2 Cache is located on the processor itself; runs at full clock speed..
L2 Cache or Level 2 Cache is on the motherboard; runs at up to half full clock speed.
There is one other type, which is ATC (Advanced Transfer Cache) which is Level 2, not on the processor, but is configured to run at full clock speed.

If you plan on using your PC for games and complex graphics or 3D work, you'll want L1 Cache---as much and as fast as possible. It will deliver sigificant spoeed improvement.

One other technological innovation woth mentioning here is something known a "Multimedia Instruction Sets." The first Multimedia Instruction Set was developed by Intel, called MMX, AMD answered with 3DNow! and Intel has recently released a set called SSE for Pentium III processors and SIMD2 for Pentium 4s. Briefly, Multimedia Instruction Sets are designed to improve performance with 3D applications---assisting in re-drawing, rendering, etc. Multimedia Instruction Sets will only work with applications that support them.

CPUs: The Final Word
Here are a few other considerations when selecting a processor for a new system or as an upgrade.

What Type Of CPU Do You Really Need? Most PC users these days want the fastest possible processor. While some computer users will always need faster processing, others may buy more than they need. Consider the computing power required to add digital special effects to motion pictures, like Titanic or Pearl Harbor. These tasks gobble up massive amounts of processing. Or computer-generated images, as seen in Toy Story or Shreck. Even retouching large digital images in Adobe Photoshop or Corel DRAW requires a powerful processor. If you are planning on using your PC for any type of image editing, 3D design or rendering, or video production, you'll want to invest in the fastest possible CPU, ideally a Pentium III, Pentium 4 or AMD Athlon.

However, if your activities are confined to surfing the web, word processing, spreadsheets and e-mail, you can save money by selecting a slower processor, perhaps an Intel Celeron or AMD Duron. Put those savings into additional memory, which will speed up all your PC's functions, not just the processing of data.

But there's more to the equation. If you have a video card which includes an onboard graphics processor (which assists the CPU in processing video data), you may not need to invest in a premium-speed processor. Save a few bucks and let the video card's processor help with the heavy lifting...

And one other suggestion. Don't put all your eggs in one basket by buying a high-end processor and skimping on the memory and motherboard. As we've seen, they all work together to move and process data. Buy a solid motherboard with as much memory as possible, then buy the fastest CPU. This is our standard avice to our customers.

Heatsink And Fan. Processors generate enormous amounts of heat that must be dissipated within the case of your system. Running one of today's high-speed processors without a heatsink and fan will allow extreme high temperatures to build up within the PC case and ultimately damage components. If you purchase a RETAIL processor from Intel, AMD or Via, a heatsink and fan will be included. If you buy an OEM version,

A heatsink and fan may NOT be included. If a heatsink is NOT included with your new CPU, we can advise you on a compatible unit that will provide protection for your system..

Warranty. We have found that CPUs are among the most reliable electronic devices in the world, manufactured in advanced facilities. Failure rates are minute and we rarely get returns. Intel and AMD both offer 3-year warranties for retail versions. OEM warranties vary, be sure to ask when you make your purchase. But chances are, they'll work.