If there is one thing that keeps people from even considering building their own PCs, it’s the confusion that exists over CPUs (central processing units, also known as processors) and motherboards. As you will see, there is a whole raft of considerations to take into account, so people often come away from looking in stores or catalogs with the feeling that it’s easy to make a costly mistake by buying something wrong.
In this tutorial, I will lift this veil of confusion and explain what all the different technologies and options really mean.
CPUs and Motherboards: The Brain and Nervous System of Your Computer
The CPU is the brain of the PC. This is the component where the data processing is carried out and where all the instructions are interpreted. This single component is at the heart of everything a PC does.
If the CPU is the brain, then the motherboard is the nervous system, responsible for carrying data to and from other devices in the PC and connected to it. The CPU fits into the motherboard via a socket called a ZIF socket. (ZIF stands for Zero Insertion Force, and the hundreds of pins on the base of the CPU are designed to slip effortlessly into the socket.)
The motherboard provides the circuitry that forms the pathways between the CPU and the RAM, hard drives, optical drives (CD/DVD drives), expansion cards, and other devices. As well as carrying data to and from other components, the motherboard is responsible for carrying power to these devices.
Both of these components are crucial to a PC and getting the right components will make the difference between an excellent PC, a good PC, and a poor PC.
CPU Terminology: The Roots of Confusion
Give people a set of choices and, rather than giving them options, you just end up confusing them! When it comes to choosing a CPU, a flurry of questions spring into mind, and these aren’t readily answered:
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Why is there more than one option?
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What’s the difference?
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What are the pros and cons of each?
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Which is best for me?
CPUs are one area that causes people a lot of confusion and frustration. Basically, there are two major corporations competing in the PC arena. These are:
Both AMD and Intel make world class CPUs. Both make CPUs that cover the whole consumer spectrum: budget CPUs, low-power consumption CPUs for mobile devices, midrange CPUs, and high-performance CPUs. Both manufacturers are very popular.
So what’s the difference?
The Difference between CPU Manufacturers
The bottom line is that there’s in fact very little difference between CPU manufacturers. Just as there are dozens of car companies all selling cars, the same is true of CPUs, but instead of there being dozens of companies manufacturing and selling CPUs, there are only two companies making and selling CPUs for the PC market: AMD and Intel. In fact, it’s quite possible that if there were half a dozen or so CPU manufacturers, consumers would be more comfortable with the idea that AMD and Intel are competing manufacturers as opposed to making products that work differently.
One of the reasons that consumers are confused by the difference between Intel and AMD products and have a belief that the CPUs are very different comes from the fact that the Apple Macintosh computers are so fundamentally different from the PC—so different that the Windows operating system won’t run on a Macintosh. (However, Apple has now recently announced a shift from CPUs made by IBM to CPUs made by Intel, so things are bound to change.)
Choices, Choices, Choices . . .
From a point of view of performance and power, a case can be argued for both AMD and Intel CPUs.Take a look at computer magazines or surf the web for info, and you’ll come across reams of reports and tests and comparisons—some independent, some not. Some will conclude that AMD CPUs (or more specifically, a particular AMD CPU) are better than Intel CPUs and that consumers looking for a good deal should choose AMD. Then within minutes, you’ll come across another report or test that says that an Intel CPU is best and that’s the CPU of choice and everyone should go for an Intel CPU.
Opinions are everywhere. The media, web, magazines, and newspapers fill their pages with them. And most are just that—opinions.
The truth is that both companies make powerful and reliable CPUs.Take two PCs of similar specification, and it’s impossible to tell the difference without actually looking at the CPU or using software to tell you what it is.
For the purposes of this book, we are going to assume that there are no performance or power differences between AMD and Intel CPUs. For the project in the book, we will be using an AMD CPU, but you are free to choose either AMD or Intel for the PC you build. No matter which you choose, you’ll get a high-quality CPU.
The Real Difference Is . . .
The real differences between AMD and Intel CPUs are in the underlying architecture of the CPU. This is the inner circuitry of the CPU, what makes it work.
A modern CPU is a mind-bogglingly complicated piece of engineering, and it crams a lot of sophisticated technology into a small space. Just as a Ford and Ferrari both have four wheels, have seats, and use an internal combustion engine to take people from A to B and back to A again, AMD and Intel do the same thing, but in different ways.
You can’t take an engine out of a Ford and expect it to fit directly into a Ferrari, and the same is true of AMD and Intel CPUs. One of the main differences between the two manufacturers is that each CPU requires a specific motherboard.
What This Means to You
This means that no matter which CPU brand you choose, you need to make sure that the motherboard is designed to support the CPU. (That brand is, for example, whether you choose an Intel CPU or an AMD one. Each manufacturer will have a number of CPUs available covering the whole range, from budget to high performance.) And not only do you need to get a motherboard that’s compatible with the CPU manufacturer you’ll need a motherboard that’s compatible with the type of CPU that you want.
If you want to use an Intel CPU then you need an Intel-compatible motherboard. If you go the AMD route, then you’ll have to have an AMD-compatible board. There’s no point buying a CPU and then buying a random motherboard—there’s a good chance it won’t be compatible. After you know that your CPU brand is compatible with your motherboard, you need to make sure that your CPU model works with your motherboard. This is where things begin to get a little complicated, and you have to be careful so as not to make a mistake that could cost you money. Motherboards are designed to support a particular range of CPUs and no others. This is very specific, and it’s important to get it right. Generally, it’s not possible to fit an incompatible CPU onto a motherboard, but this doesn’t stop people trying and then damaging the CPU, motherboard or both in the process. The main controlling factor is the CPU socket type.
Motherboards and CPUs are closely linked, and this makes future upgrading of a CPU or motherboard difficult. CPUs change regularly, and every year or so new ones will replace the old and the manufacturers quickly stop making the old model, preferring to sell the newer technology. This means that as a general rule of thumb, if you try to upgrade a PC that is more than a year old, any upgrade involving the CPU or motherboard will be difficult because you will need to change both for them to be compatible (and there’s a good chance that you’ll need to swap out the RAM too at the same time).
RAM upgrades are much easier because manufacturers continue making old types of RAM long after the technology has been superseded.
Both Intel and AMD make motherboards, but don’t be restricted by thinking that they are the only ones—there are half a dozen or so good motherboard manufacturers. Just a few of the names to look out for are:
- ASUS
- Abit
- Gigabyte
- Microstar
- MSI
- Tyan
- DFI
So, you either have to choose a CPU and get a motherboard to match or choose a motherboard and get a matching CPU.We recommend that you choose the CPU first because there are more considerations to take into account when buying a CPU than there are when buying a matching motherboard. Because of this we’re now going to move on to examining how to choose the right CPU for you.
The Important Differences between CPUs Let’s take a look at some of the differences between CPUs that actually make a difference. These include:
- Speed
- Socket types
- Cache (built-in memory)
- Dual-core/hyper-threading/64-bit processors
CPU Speed The most significant difference among CPUs is the speed. That is, how fast it can process instructions? The faster it can process instructions, the faster we perceive the PC to be.
Every PC is regulated by an internal clock. This clock regulates the rate at which instructions are processed by the CPU. This is known as clock cycles, and it determines the interval between successive instructions. The smaller the interval, the faster the CPU can process instructions and the faster the perceived speed.
CPU Sockets
Remember how we said that the socket the CPU fits into determines the type of motherboard you can use? The reason for this is because CPUs fit onto the motherboard via a socket. The pins on the CPU have to fit into a specific socket on the motherboard. Different CPUs have different pin configurations and, therefore, need to be fitted into a different socket.
Cache
When looking through specifications on CPUs, you will undoubtedly come across mention of “cache,” “on-board cache,” “on-die cache,” or “L1” and “L2” cache. These terms all refer to the amount of memory built into the CPU. The more memory that is built into the CPU, the faster the CPU and the better the performance.
The size of the cache varies for different CPUs, from 256 KB for the lower performance budget CPUs to 1 MB for high-performance CPUs such as the AMD Athlon 64.
Dual-Core/Hyper-Threading/64-Bit Processors
AMD and Intel both have a range of processors called “dual-core,” which basically means two CPUs in one that offer greater power. Intel on the other hand has Hyper-Threading Technology; this allows the CPU to run some applications faster because it can run multiple computer instructions in parallel, which increases speed.
Motherboard Features
Now that you’ve looked at the different kinds of CPU available and looked at the terminology that cloaks them, it’s time to take a look at the motherboard.
There are two types of motherboard features—standard features that are found on every motherboard and additional features only found on some motherboards.
Standard Motherboard Features Standard motherboard features include:
- CPU socket
- RAM slots
- Chipset
- PCI expansion card slots
- AGP/PCI Express expansion slot (for video adaptor)
- Hard drive/optical drive connectors (IDE/SATA)
- Floppy drive connector
- Power connectors (to accept power from the PSU)
- Connectors for CPU and case fans
- Keyboard socket
- Mouse port
- Serial/parallel port
- USB ports
Most people wonder what the battery on the motherboard does. This battery serves two purposes: it powers the PC system clock that keeps track of the date and time, and it also provides power to the CMOS (complimentary metal oxide semiconductor) to store the BIOS (basic input/output system) settings.
These batteries are very reliable and will last for many years.
Optional Motherboard Features Additional features that may or may not be present on a motherboard (depending on price and quality) include:
On-board video adapter: Buying a motherboard with an on-board video adaptor saves on your having to purchase a separate video adaptor. On-board video adaptors are usually poorer quality and provide less power than a separate video adaptor, but they are ideal for office PCs or PCs that play low-specification games.
On-board video adaptors use a portion of system RAM for graphics processing (usually between 8 and 64 MB, the more RAM they use, the better they perform) so you might want to purchase additional RAM for the system. (See Chapter 5, “Choosing the Right RAM.”)
On-board modem: For those who still use a modem or connect to the web or send faxes, this can save on having to buy a separate modem.
On-board network adapter: More and more PCs connect to a network nowadays, and an on-board network card can be a useful feature.
Additional USB ports: With so many USB devices you can’t get enough USB ports!
FireWire ports: Some devices (especially video cameras and external hard drives/optical drives) either require a FireWire port or can make use of either a USB or FireWire port. Having a couple of FireWire ports on a system is handy in case they are needed in the future.
