DIY Computers


Home >> Hardware Basics

Random Access Memory or RAM


Random Access Memory or RAM is often referred to simply as memory. The RAM is a collection of integrated circuits where information is stored when the computer is executing a program and/or manipulating data and can be likened to the machines "head space", how much it can think about. If the data is larger than the available amount of memory it has to write it down temporarily on the hard drive, usually in a thing called a swapfile. Memory and swapspace (often called virtual memory) are important factors in a computers performance. If you are using a computer aided design program to create a complicated engineering drawing for example the computer will attempt to load as much of the drawing program and the drawing itself into its RAM where it can be manipulated quickly. If the computer does not have enough RAM to store all of the drawing it will write the portion of the drawing it is not using to the hard disk drive. As reading and writing data to the RAM is far faster than reading and writing data to a hard disk drive many programs will benefit from having a large amount of RAM to minimise this effect. If you move to the part of the drawing that is stored in the swapfile the computer will have to write the currently displayed portion of the drawing to the swapfile and then load the part of the drawing you are moving to into the RAM. This process is referred to as swapping and it can be the death of good computer performance. It is also the exact reason why we should always leave a few gigabytes free on our hard disk drive. The computer will not be able to function if there is no space left on your drive to write a swapfile.

There are many different types of RAM and you should ensure that the memory you are purchasing is compatible with your motherboard. Although there are slight differences in the speed of RAM, capacity and brand remain the largest choices when making a purchase for a new computer. If purchasing RAM for an older computer it may be wise if possible to bring the RAM to you hardware vendor. RAM, much like processors, has evolved over the years and this has resulted in a number of choices as far as RAM type and the type of slot on the motherboard that the memory is inserted into is not interchangable between them.

Most motherboards have at least two slots that RAM is inserted into however some have four, six or even eight. If you install 2 X 512mb RAM modules your computer will then have 1024mb (1gb) of RAM. Many motherboards have a feature called dual channel memory architecture which utilizes two 64bit channels instead of one effectively doubling the throughput of the memory. Dual Channel memory works at its best if all memory used in the computer is identical in speed, size and chip arrangements. Some memory manufacturers offer matched sets of memory.

The amount of RAM your computer really needs is determined by the machines intended use. If you are using windows XP or most versions of linux you should have at least 512mb for the machine to be comfortable. Windows Vista prefers 1gb of RAM. If you are playing computer games or using more intensive applications you may prefer to double these recommendations. If you are manipulating massive amounts of data such as our computer aided design example consider tripling them. If the machine is going to be used for one particular application consider contacting the programs manufacturer and finding out the recommended system requirements.

Installing RAM


The installation of memory is pretty straight forward and easy. Care must be taken to ensure that the key in the memory slot on the mainboard lines up with the slot in the memory.

  1. Move the ejector tabs into the open position as shown on the upper slot in this diagram
  2. Gently slide the RAM into the slot taking care to ensure the key on the slot lines up with the notch on the memory module
  3. When you are certain the RAM is sitting correctly push down on it firmly and squarely until the ejector tabs move into the closed position as shown

Installing Memory