RAM - What is It & Why You Need Plenty

This is the first article in the Understanding Your Computer series from aworldofhelp.com. Our goal is to help people understand how their computer works, not simply tell them what they need to buy or use. When you know how your computer works, buying the right system or upgrade is easy. The series is designed to provide valuable information to users of all knowledge levels, so if part of it seems too complicated or too simple for you, I hope you read on and get all you can out of the articles. If you have questions or comments about this or any article, please ask in the forums!

RAM - What is it & why you need plenty

Many people picture a computer as consisting in part of a

Processor - CPU

Memory - RAM

Hard Drive

The way these three components interact is important to understanding how a computer works, and ultimately to understanding why you need enough RAM for your programs. Around the Internet and in Magazines you can find recommended RAM amounts for typical users. You also will find many places proclaiming RAM as the best performance for your dollar upgrade. I don't disagree at all, but I want you to understand what RAM actually does, and why it can be such a valuable upgrade.

I covered this subject briefly in the aworldofhelp Notebook Buyer's Guide on page 4. The information in that article is accurate, but I want to try to make things a little clearer here.

The article is divided into four sections, covering:

1. The functions of the three components we are discussing and their relative speeds

2. Why you need RAM and what takes up RAM

3. Multitasking and how RAM improves performance

4. How much RAM you need

CPU stands for Central Processing Unit. It is the brain of your computer. When you open a program, like Microsoft Word for example, the CPU reads through lines of computer code and follows the instructions so you can use your program. When you play an audio file like an MP3, the CPU has to do work to decompress it while it plays. When you edit a picture the CPU has to perform many calculations to make even the smallest changes.

One thing to note is that the CPU actually does have a very small amount of memory in it. This is the fastest memory in a computer system, but it is so small it doesn't really affect this article. Generally speaking, the CPU doesn't store the information that makes up the program, MP3, or picture, it only processes it. The data has to be located somewhere in your computer, and the CPU has to find it and then retrieve it.

That action, the problem of locating the data and how it affects your overall system performance is what this article is about.

RAM

RAM stands for Random Access Memory. This memory is very fast, and you will see it in sizes like 256 MB, 512 MB, or 1024 MB. When you turn off your computer, the contents are erased, so it is only temporary memory. This is where the CPU looks first to get data to process. So if you are editing a picture, and its data is in this RAM, because RAM is fast memory, editing the picture will happen relatively quickly.

Hard Drive

Your Hard Drive is where you store all of your programs, music, video, and everything you keep on your computer. This is the memory where you store your files that remain even after you turn your system off. You will see them in all sizes, now typically ranging from 30 GB, to hundreds of GB. Hard drives are very slow compared to your CPU and RAM because they are mechanical. Inside the disk there are actually small readers that physically move around to locate and read data.

If you are editing a picture, the CPU will first look in RAM memory to see if it is there, because RAM is fast. If it isn't, the CPU will go to the hard drive and edit the picture there. Because your hard drive is so slow, this takes a much longer time than if the picture had been in RAM.

Again, the CPU only stores a tiny bit of data