Since the earliest IBM PC computers, consumers have had the option of putting together their own computer system from compatible components. In the earliest days, this offered a significant savings for consumers who were willing to buy third party parts from smaller manufacturers. Things have changed a lot since then, but there are still significant advantages to building a machine from parts rather than buying a pre-built system.
I personally have not purchased a pre-built desktop computer system since my parents bought an Apple IIe that I technically didn't purchase. To me the advantages of getting the exact computer that I want over what a company feels I might want outweigh the disadvantages of building one.
A System Is A Sum Of Its Parts
All computer systems sold on the market are a collection of components that provide a functional computing system. Processors, memory and drives are just some of the components that make up a system and allow us to differentiate one system from another. As such, the performance and quality of a system is determined by the parts used in its construction.
So what is the difference between a store bought system and a custom built machine from parts? There could be almost no difference to a very significant difference based on the parts selected for the machine. With this in mind, let's examine some of the advantages and disadvantages of building a computer from parts rather than buying a system.
Advantages of Building
The most distinguishing advantage to building a computer from scratch is the selection of parts. Most computer systems come pre-built with the specifications and components already selected for you. This often can lead the user to have to sacrifice certain features that they may not want to give up. By building a computer from components, the user is able to choose the parts that best match the computer system they desire. Some vendors do allow you to customize a computer system, but you are still limited to their selection of parts.
Another thing that users may not be aware of with pre-built systems is that two of the exact same model computer can actually have very different parts. The reason for this has to do with suppliers, parts available at the time the system was built and just pure luck. For example, Dell might switch between multiple suppliers of memory because one is less expensive then the other. Buying all the parts on your own guarantees what parts you will get in your PC.
One of the less tangible advantages to building a computer from scratch is knowledge. By building a computer from scratch, a user is able to learn and understand how the parts work together. This information becomes immensely valuable when troubleshooting computer problems. The knowledge of what components control the different sub-systems of a computer means users can repair their own hardware problems without having to deal with support groups or expensive repair labor bills.
Disadvantages of Building
The biggest disadvantage with building a computer is the lack of any one support organization you will be dealing with. Since each component can and likely will come from a different manufacturer and/or store means that if a part has a problem, you will have to deal with the appropriate company. With pre-built systems, you only have to deal with the manufacturer and their warranty service groups.
The second biggest disadvantage with building a computer system is cost. In most cases, the cost of building a computer will be slightly more expensive than purchasing a pre-built computer. This is due to the fact that the manufacturers can buy in bulk for steep discounts that translate into savings on the computer system. They also include software with the systems that must be purchased separately when building a system. OEM software purchased with hardware does help reduce the costs on custom built systems.
The cost disadvantage does not always hold true though. As the more money one is willing to spend on a computer system, the more likely you will be able to save money by building the PC yourself. This has to do with the top of the line specialized systems are often marked up for extra profits per unit by the manufacturers. So, if you are looking to spend big, investigate building it yourself first.
How to Build a Computer
Now that all of that is out in the open, those interested in building their own computer system from parts can take the next steps. There are a large number of resources available here at the About.com PC Hardware / Reviews site to assist those willing to build a desktop computer. This information has been collected together and is now available in a 5-day e-mail course.
This course covers the basics of the tools and parts you will need, how to put them together properly and even how to get the BIOS configured so that the operating system can be properly installed. This same information can be found on this site, but this makes it easier for users to digest the information without being overwhelmed.
Previously users did not have the ability to build their own notebook computers. Even this is changing these days. Several companies now sell base systems that are referred to as White Box Notebooks. These have the base components such as chassis, screen and motherboard already installed. Users can then select items such as memory, drives, processors and sometimes graphics to finalize their own laptop computer.
Don't forget to research the parts as well. There are a wide range of components available for consumers to choose from. It is not possible for sites like the PC Hardware / Reviews to look at even single one of these. I do have some lists that I periodically update for items such as desktop CPUs, hard drives, DVDs, Blu-ray and video cards. These are a good starting point for selecting parts.