All About Memory

It’s back to talking about memory this week on K-S! We’ve talked about this one before, but it bears repeating and I’ve added new info!

Jump to section about:

RAM Hard Drives Proper terminology What’s a GB?

Breaking Hard Drives Solid State Drives? Flash Memory

RAM

You may have heard the term “RAM” bandied about. RAM is a computer’s version of short term memory and stands for Random Access Memory. This memory is only ever in use when the computer is turned on, and gets completely erased every time it is turned off. It’s a sort of “mental” workspace for the computer to use, providing very quick access to information it needs the fastest and most often. Nowadays, the RAM in a computer is typically somewhere between 1 GB and 4 GB. I’ll explain “GB” down the page.

Hard Drives
The hard drive is a computer’s long-term memory. Unlike RAM, the hard drive is not completely erased when the computer is off. That would be really annoying.
Hard drives can hold hundreds of times the amount of data that RAM can, but are also a great deal slower in comparison. So, when you do something like play a song file or open a document, it is usually copied from the hard drive to the RAM so the computer can read it quickly.

Hard drives are usually made of one or more spinning platters that are covered in millions of tiny magnetic bits. The platters are read by a bunch of little heads, much like a super high-tech record player. Hard drives these days have somewhere between 20 to 750 GB.

So they’re both called Memory?
No! While hard drive space is technically memory, it is incorrect to call it that. When talking about computers, the term “memory” refers to the RAM. If you want to know how many files you can permanently store on it, you must ask: “how big is the hard drive?” or “how much disk space does it have?” Please don’t mix those terms up. Every time you ask about “memory”, wondering about permanent file storage, your IT administrator or computer-savvy friend/sibling/acquaintance/ninja gets an instant migraine.

Wait, what’s a “GB”?
GB stands for gigabyte, and is commonly just called a “gig” or “gigs.” A gigabyte is roughly a billion “bytes.” (1,073,741,82 to be exact.) And a “byte” is a set of eight one’s and zeros that make a character, like this A or this F. Each letter on this screen is about one byte.

(20 is not very much space for a hard drive. 750 is a lot. On the other hand, 2 GB is pretty good for a USB flash drive and not bad for a computer.)

Want some examples as to how much space certain files take up? One MP3 song might take up about 5 MB (megabytes, or megs.) Since there are 1000 MB in a single GB, that means you could store a lot of songs on an 8 GB MP3 player! Video files and software programs can take up several GB a piece. A single email message is about 3 KB (there are one million KB or kilobytes in a GB.)

Breaking Hard Drives
Is so easy anyone can do it! Because hard drives are like little magnetic record players that spin very fast (between 5,400 and 10,000 rotations per minute) it’s important that they not be bumped too hard. Especially if your laptop is on, you shouldn’t jerk it around or let it fall down the stairs or something. That can make the little arms inside scratch across the platters as they read the data, which will permanently damage your drive. This can also happen if it’s off, so be careful.

Solid State Drives
That said, there are new kinds of hard drives out called Solid State Drives (SSD). Unlike traditional drives, these ones have no moving parts, thus making them harder to break. They’re also generally faster and use less power than the spinning kind and are essentially very large flash drives. The drawbacks are that they don’t have the same kind of capacity that spinning drives do (yet) and have exorbitantly higher prices.

Flash Memory
Speaking of SSDs, you may well already have a small one kicking around somewhere in the form of a USB drive or a memory card. These use what is called “flash memory” which gets its name from its ability to be written to but mostly erased in a “flash”. They’re called “memory cards” when, well, when they’re in card shape, and USB drives when they have a USB connector.

Confused? Yeah, there’s a lot of them. Click on over HERE for a good guide which explains them all!

Well that’s it for this week! Thanks for reading Knowing-Stuff!