/computer./spec/memory

When we purchase computer we compare the specs and choose it according to the specs.
So even if we are not technical geeks we still need to understand the meaning of computer specs as a part of common knowledge. If you are also the people who want to understand , this article might be helpful.

There are three kinds of memory in your computer which are normally listed in the specs: one is RAM(Random Access Memory) and the other is Hard Drive Memory. And the third one is Cache memory. I will not talk about Cache memory here.

I can a make good metaphor about RAM memory and Hard Drive Memory.
RAM memory is like a cutting board and Hard Drive is like a fridge.
If we have a big cutting board, we can deal with many things simultaneously and if we have big fridge, we can store many things.
In average, the size of each movie is around 1GB (1 gigabyte) and one song is 4MB (4 megabyte).
(1GB=1000MB)
If you need to deal with many things simultaneously, you need a big cutting board.
If you need to store many things, you need a big fridge.

In average, Modern computer is sold with 100GB hard drive and 1 or 2 GB RAM memory.
In my computer, I have 100GB hard drive and I am using 4 GB in my hard drive.
My fridge is quite empty at the moment.

Here I would like to describe exactly.
RAM memory : this is a fast memory to store current operational information - the data you are currently working with, such as currently open documents, pictures which you
are viewing, program which you are running including operation system. This memory is very fast on reading and writing operations (average 1.6 gigabyte per second), but has 2 disadvantages:
1) It's temporary. The information stored in the RAM exists only while the computer is working. After you switch it off all the information in RAM is lost. That's why each time you switch your computer on, you need to load lots of stuff from your hard drive.
2) It's expensive. In average, 75$ per gigabyte of memory.

Hard Drive : the memory to store data permanently. It stores the data by writing them onto metal plates of a hard drive by magnetizing them. It means that even after you switch your computer off, the information will not be lost. Hard drives are cheap at present - you can buy one for around 150$ with 120 Gigabyte capacity. It makes the price of hard drive memory 0.8$ per gigabyte. That is roughly 100 times cheaper than RAM. But the speed of a hard drive reading and writing operations is also less - around 100 megabyte ( =0.1 gigabyte) per second, that is around 16 times slower than RAM.


unless you are going to use your computer for memory-intensive tasks like 3D or video design,Generally, 1 gigabyte RAM is more than enough if you are going to use Windows XP or Linux operation system. I have 1 GB RAM find it more than enough.
Concerning hard drive, I use only 4GB out of 100 (4%) of my hard drive capacity. It means that the money I paid for my hard drive is used inefficiently. Unless you are going to store a hundred movies on your hard drive, you don't need the biggest one.



RAM memory (http://en.wikipedia.org/wiki/Random_Access_Memory)
Hard Drive (http://en.wikipedia.org/wiki/Hard_disk)