Thursday, August 29, 2013

Is it Technology Day again, already?

Yes, it is!

So, what to talk about again?  I know!  Let's talk about something lots of people get mixed up about.


Human beings have a lot of it.  We can remember stuff that happened decades ago, conversations, road trips, immense amounts of data, stuck up there, just waiting for a trigger to help us remember.  Problem is, it's not really very well indexed.

With computers, that's a bit easier.  But wait, humans only have one kind of memory - the wet stuff.  In between the ears wet.

With your PC or Mac, there are two kinds of memory, but geeks use two different words to describe them so we all know which ones we are talking about.

In reality, they really are different, so the different words make sense.  First, we've got what is more commonly known as Storage.  Hard drives, flash drives, floppy disks, and a host of other, older types of storage are sometimes referred to by the uninitiated consumer as memory.  It isn't memory, it is storage, because that's what we do with it, store stuff on it.

Your computer's Operating System, the applications (or programs) you use on it, the data that results from your application usage - all of it has to reside somewhere so your computer can find it, read it and present it to you so you can do with it what you wish.  That's storage.

Remember last week when I talked about Megabytes and Gigabytes and so forth?  That's the measuring standard we use to tell how much data we can put on a particular item of storage.  Hard disks are usually of greater capacity, followed by flash drives, floppy disks and other older types of storage.  A newer kind of storage, similar in use to Hard Drives is called Flash Storage.  Similar in its basic construction to flash drives, these new drives have no moving parts, boast faster read/write times and help computers boot over twice as fast as those equipped with standard disk based hard drives.  However, they usually are of smaller capacity, and are much more expensive, due to the more recent entry into the market place.

What all of these things have in common is that they are what we call non-volatile, or permanent storage.  You can turn off the computer, come back later, and the data is still preserved intact.

The other type of memory is called RAM.  That's short for Random Access Memory.  Yep, that's memory!  It is NOT storage, because it is volatile memory - when you turn off the power, the data stored there disappears.

What is RAM for, and why do you need a lot of it?

A computer is, as I said last week, a rather dumb machine.  It needs you to tell it every move to make.  Line by line of instructions, called code, does this.  That's what Programs (or Applications) are for.  They contain the code that allows you to tell the computer what you want it to do.

Those apps are stored on the Hard Drive.  Storage.  Kind of like a book shelf.

Think about the RAM as your desktop.

You have a task to perform, so you turn around, take the book with the instructions in it from the bookshelf and put it on your desktop.  Every time you have to perform one part of your task, you turn to that book for the next set of instructions.  When that task is finished, you put the book back.

That's what the computer does with RAM.  When you open a program, the computer reads the main portion of the code for that program into RAM, where it is more easily accessible.  (RAM is MUCH faster to read than a hard disk is, so it takes less time to read the instructions from there.)  When you finish, it "wipes" that portion of RAM, making it useful for holding another program's code.

The more RAM you have, the more programs you can open at one time, or the more data you can manipulate at once, like video or pictures.

RAM's size is also measured in Megabytes or, these days, in Gigabytes, to show how much data can be temporarily kept there.   More RAM not only helps you open and use more apps, it also makes your Operating System seem faster, since it can store more of the code from the OS in the faster RAM, so it takes less time to read new lines of code.  Less time reading or writing, the faster things seem to be.

I hope this makes things a bit more clear!

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