AskTOOZE: RAM, HDD and how they work together


I’ve been using the computer for a while, but when I recently wanted to get myself a new one, I was stumped by all the technical jargon, especially RAM. Can you share a little about the parts that go into a computer, and how they work together? Thanks!


DT: Looks like this mail is for you.

XY: Isn’t this stuff easily found on Wikis via Google?

DT: I thought so too, so I went to google RAM. Turns out that the articles available are too technical; it’s embarrassing but I still didn’t understand after reading those articles. It’s nice if we could draw a parallel to something simpler like workspaces.

XY: What do you mean when you say technical?

DT: There’s a lot of words spent on the technology of RAM, but little on what it actually does. More importantly, I (and I believe our readers) want to know how RAM and the other parts fit in together into the larger picture of a computer.

XY: Where do you want to start?

DT: Why don’t we start with RAM?

XY: Think of RAM as your working desk. And your programs (or applications — apps) as your piles of working paper, while you (the user) are the Central Processing Unit (CPU) which does the work.

If you have a small desk, you will find it hard to work on many things at once; things tend to get cluttered and messy. A bigger desk will allow you to work on more stuff without having to put things away. With a larger desk, one is also able to work on larger projects and documents.

DT: Ok… how does a hard disk (HDD) fit in then?

XY: Using the same work space analogy, the hard disk will be like your file cabinet. When you do work on your computer, you are essentially making a copy of your documents (stored in the cabinet — HDD) and placing them on your desk (the RAM).

If your RAM is too little, virtual memory which makes use of your hard disk space comes into play. It’s akin to you having to keep parts of your documents in the cabinet and swapping them to and fro your desk and cabinet as you do not have enough space on the desk.

DT: Let me try adding references to my hard disk (HDD) while we are at it. Am I right to say that when I fire up an app, I get data from the HDD and dump it on the RAM? Does the information on the HDD change?

In other words, can I theoretically open a program and disconnect the HDD? It’s like having my papers on the desk and then removing the cabinet is it not?

XY: Yea, but if you lose power you lose your unsaved data, because unlike the physical idea of papers on a desk, RAM actually clears out its memory when it is unpowered.

DT: By unpowered you mean at every instance of shutdown or reboot?

XY: Yea. Think of it as a cleaner removing everything off your desk every night.

DT: Let’s see if I understand so far. When I open a document, I make a copy of the files in the HDD and place it in the RAM for working. Until I save, every change I make is in the RAM; when I hit save, the data on the RAM then gets copied back to the HDD for storage. And the data on my RAM remains until it gets swapped out due to lack of space, or when I power down.

How does the RAM know which data to swap with the HDD in virtual memory?

XY: Simple. The operating system does it all in the background by moving unused areas in your RAM back (such as a minimized window which has not been open for some time) onto the HDD, freeing it up for new apps. The problem only comes when there is too little RAM and stuff keeps moving in and out. You will notice the HDD “thrashing” around and that’s when we would experience the “my computer is so slow” syndrome.

DT: Now that I’m clearer about RAM and HDD, let me ask about solid state drives (SSDs). SSDs are flash based HDD with no mechanical moving parts — something like a giant flash drive, and they are supposedly to be über fast. Since I can theoretically swap data between my RAM and HDD (in the work space analogy, between the desk and the cabinet) superbly fast, can I actually get by with less RAM if I am using a SSD?

XY: You are right to say that a SSD is a flash based storage resulting in higher read speeds. What it means for users is that we can retrieve our stuff faster.

However, even with a SSD and the fast switching between your cabinet and table, RAM is still important. This is because having a bigger desk (more RAM) allows you to keep not just your current work on the desk, but also all your other frequent tools like stationery and supporting stuff (other apps and utilities, not just your documents) easily accessible on hand without having to look in the drawer each time. Besides, RAM is pretty cheap nowadays compared to the cost of a SSD.

Also, games favor more RAM. Sure you can write a report on a crammed desk, but it will be much harder to play a game of Risk without clearing out some space. I’m sure you don’t like to keep the dice and troops in a drawer only to have to look for them each turn right?

DT: Well that pretty much settles the part about RAM and HDD, with a little about CPU. How about you finish off with the last hardware: the motherboard?

XY: The motherboard is the circuit board which houses all your other components. Think of it as your office floor (literally) where your desk, cabinet, worker (you — the CPU) reside.

I guess that’s enough for today. Till then, keep the letters coming in!


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