This chapter is a field guide to hardware selection. Although hardware is in a constant state of flux, the good news is that an old adage applies: The more things change, the more they stay the same. If you can see computer hardware in more abstract terms, you have everything you need to make an educated purchase. Despite the constant escalation of specifications, a computer still has a processor (CPU), random-access memory (RAM), secondary storage, and some

I/O devices. Every now and then, some underlying technology may change, but nothing is going to stop memory from doing anything other than storing a bunch of ones and zeros.

Here are three guidelines that you should remember:

• Know what you want, and don't lose sight of it This usually comes down to a price versus performance trade-off, but details such as ergonomics can be just as important.

• Don't listen to vendors They generally want to sell you the most expensive thing in the store even though it may not even work correctly. In addition, these people are trained to sell systems for Windows users — in most cases they're not aware of hardware issues important to Linux users.

• You often get what you pay for However, refer to Rule 1 first: is the more expensive hardware what you really need and want?