I TEND to remember things that are of no use or value whatsoever, like the atomic weight of cobalt, which is 58.9.  The more relevant details of my life, where I'm supposed to be, when I'm supposed to be there, to actually bring the things I'm supposed to be taking places... that's the real science.

I've long hoped for the time when computer component miniaturisation reaches the point where hard disks are small enough to be ingested in order to boost brain and memory capacity.  Alas, it has yet to be achieved.  This, however, leads me tenuously to the point of this article.

The Confusion

When most people refer to "memory" in computing, drawing on their own interpretation of what human memory is, this is what they think of: People remembering things.  Storing information.  Recalling memories.  In the world of computing, however, it confusingly means something quite different.  This confusion has led to people believing that deleting old or superfluous files from their hard disks will speed their computer up, or that refering to "memory" is refering to storage.

Storage and memory are two entirely different things in computing. Fundamentally similar, serving two separate functions, they are both equally necessary in today's computing architecture.

Storage is carried out by the computer's hard disk. The purpose of this is to hold data when the computer is powered down so that it can be recalled when it is switched back on.

Memory is handled by... the memory, also known as RAM (Random Access Memory). The purpose of RAM is to hold the data that is currently being used by the computer. Any files that the user has open, any programs that are running, any music that is playing... will be held in the system memory while the computer is using them.  When you open something on the computer, it is loaded from the hard disk into the system memory before it opens/works/displays.

Thus, both pieces of hardware perform a very similar task... they both hold data, in some capacity, at different times. So why have both, I hear you ask? Here's why: RAM cannot hold data when it is powered down.  As soon as RAM loses power, it goes completely blank. It is volatile. So, again, you ask... why use it? Because it reads and writes data thousands of times faster than the hard disk.

So, to recap:  Hard disks are slow but hold data when powered down; system memory is superfast but loses its data when powered down. You need both of these advantages when computing, and so both components are used.

What have I got?

To check your available hard disk (storage) space, open My Computer.  Windows 7 users will see something like this:

Windows assigns "drive letters" to available hard disks. Some of you will have a C: drive, others will have more.

If you do not see the meters below the disk, simply right-click the drive and click Properties. This will show you a pie chart of how much space you are using, and what the capacity is. In my case, I have two 300GB drives. This is more storage than I'll ever need.

Similarly, to check the system memory, right-click My Computer and click Properties.

Again, under Windows 7, this is what you see. The memory here is 4GB. We'll look at the rest in another article.

So... if you're still here... you may have noticed an odd variance -- 300GB of storage, but only 4GB of RAM.

Why?

The same reason your file cabinet holds more than your desk space. You're never going to have every single file open at the same time on your desk. The desk only has to hold whatever you're currently working on, after which you return it to the cabinet making space for the next one you open.

What if I run out of RAM?

Then the system starts using the hard disk for both storage and holding accessed files as an overflow. This is called "virtual memory", or "crap memory".  The result?  You hear that reassuring churning noise inside your computer, everything grinds to a halt, the hard disk light* flickers constantly, and you get angry.

Remember, the hard disk can do it, albeit thousands of times slower, creating a huge bottleneck in your system.

This usually means you need more RAM.

* The hard disk light is the one with a picture of a cylinder next to it.

What you really want to know

How much storage and memory should you have?

For storage, unless you're making five-hour home movies every weekend, any hard disk will suffice, as the smallest ones nowadays are still huge. Anything over 80GB is fine. Chances are you'll have much more.

For memory it's a little more complicated. As a general rule, I judge it based on what operating system you run:

Windows XP: 512MB (0.5GB) minimum, 1024MB (1GB) optimal.

Windows Vista: 2GB minimum, 2GB+ optimal.

Windows 7: 1GB minimum, 2GB optimal.

What affects speed?

Your storage capacity will never make the computer go faster, nor will deleting files from the hard disk.  More RAM will speed things up if your computer is too reliant on virtual memory.

Or, alternatively, read this article and remove excess junk from your existing memory.