OK, I’m going to have to be careful here. I could write a book about all the intricacies of RAM (speed, types, size etc), but for our purposes, we need to first set our focus to what RAM actually is – and why gobs of it nestled inside your computer will make your life oh-so-much better. So, I’ll sum it up in one little sentence:
RAM is fast, temporary storage used by your computer for active programs, files, and your operating system. Check out the video to actually see what it looks like and where it lives inside your PC.
That’s really all you need to know, however, if you want to dig in a little deeper, read on…
Let’s examine four things you everyone should know about RAM (Random Access Memory, by the way – That just means any of the data it holds can be accessed in any order, unlike a device like a CD where it must be read sequentially):
1. It’s temporary storage. Your computer’s RAM is what’s known as “volatile memory”. That’s a fancy way of sayin’ that if the power to the memory goes out (like you shut down or get unlucky during a thunderstorm), then the memory loses all the information it had stored. So, unlike your hard drive, when information is hanging out in RAM it’s not a permanent thing. For example, have you ever been working on a document and had the computer crash? Then you know firsthand how painfully fast you can lose data to volatile memory!
2. It’s fast. OK, so if RAM is so volatile, why do we use it at all? Why not just write EVERYTHING directly to the hard drive?
In a word, speed.
In fact, the main reason we want to have active files and programs stored in RAM vs our hard drive is because your RAM is several orders of magnitude faster than even the quickest regular hard drives (Solid Sate Drives bring it closer, but that’s another discussion).
The interesting thing here is you’ve probably already experienced what it’s like to operate a computer that was using a hard drive for these active files instead of system RAM. For example, have you ever had too many programs or files open at once? You know what happens – things slow down, and you notice a dramatic increase in hard drive activity. Without RAM, your system would be like that ALL THE TIME! Yikes!
When you run out of space in your RAM, your computer turns to the hard drive for its temporary storage needs. (Hey, it has to put the info somewhere or it would simply crash). This swap file is Virtual RAM and you already know it’s agonizingly s-l-o-w. That’s why adding more RAM speeds your system up – if you can keep all your active tasks and files in RAM you don’t slow down.
3. There’s no moving parts. That’s why it’s so quick. It’s basically just sending electrons back and forth and there’s virtually no wear and tear. For the most part, the only way RAM will fail is if it gets an unexpected jolt – RAM is very sensitive to power spikes of any kind. It’s possible it could wear out due to a few too many read / write cycles, but that’s a rare occurrence. You’re better off worrying about hurricanes in Ohio than wearing out your RAM.
Speaking of reliability…
You might be thinking, “Hey, why not use flash memory – you know the kind in flash drives and memory cards? It doesn’t lose data when powered down. Why wouldn’t that work?
Two reasons – it’s not as fast AND flash memory doesn’t tolerate read / write cycles the way volatile memory does (some flash drives are limited to only several thousand read / write cycles). If you could replace your regular memory with flash memory, you’d find that not only were you replacing “worn out” memory all the time, but your computer would also run slower. The technology is getting there though…
4. There are LOTS of types. In order to add memory to your computer, you’ll need to know the type (DDR, DDR2, or DDR3 usually), the speed, and how much memory your computer can actually handle. The easiest way to discover this is to look at your computer’s owner’s manual. Failing that, you could always pop out a strip and take it into your local computer shop and they can at least give you an idea of what you need. See our video for explicit “popping out” instructions
Special note: 32 bit operating systems can’t see past 3GB, so dumping 8GB in your 32 bit version of Windows XP won’t do you any good.
OK, that about does it for this section. Now, at this point you should understand your hard drive is for permanent storage and your RAM is for working with active files and programs. Next, we’ll look at what our CPU does to pull all this together.