Any device that holds data for a computer for a short period of time is called computer memory. If you have spent even just a little time with any computer, you will hear about RAM, Hard Disks, or CD's and DVD's. All these are means to store the information from a computer. The capacity and speed of storage varies much in these kinds of memory.

The Central Processing Unit of a computer is connected to the main memory. This main memory component is useful in storing the data and programs that are currently being run in the CPU. In modern computers the random access memory (RAM), a solid-state memory, is attached to the CPU using a memory bus. A memory bus is also called an address bus.

In addition to RAM, there may be a cache memory also, which contains small chunks of information that is to be used by the CPU soon. The idea is to reduce the fetching time, and thereby speed up the working of the CPU. Cache memory increases the throughput of the CPU, affecting the performance of the computer. In general, the RAM is the most important part of computer memory. RAM is made from integrated semiconductor chips.

RAM and Other Types of Memory:

The primary characteristic that separates RAM from other types of memory is the fact that any memory location RAM can be accessed at almost the same speed in a random manner. This is vastly different from the accessing approach used in other devices like the sequential one, used in tapes etc. Some RAM chips are volatile, meaning that as soon as the power supply is switched off to these chips, they lose all the data.

Some computers use a shadow RAM as well, which copies data present in ROM to make data availability faster, thereby helping increase the computer's speed and efficiency.

Cost:

In earlier times, the cost of computer hardware was enormous, so whenever an upgrade was required, it was much cheaper to buy the parts and do an upgrade rather than to buy a new computer. This has changed. Now the cost of hardware has gone down, and it is easier to replace the whole computer than to buy a few parts.

This fall in prices is applicable to the desktop computers used by simple homeowners only. Replacing servers and high-end computers is still very expensive, so in the case where any new function or capacity expansion is required, it is easier and cheaper to replace parts such as computer memory.

RAM Configurations:

RAM chips are available in various configurations ranging from 128 MB to 1 GB for laptops and desktops. For normal usage, this much RAM is enough. If you wish to play many games, watch movies, or work on graphics, then you will need to have more RAM as all these applications are memory hungry. In such cases, buying a new system altogether is not a very logical solution. All the computers and laptops come with internal expansion slots that can be used to expand the memory.

An optimal amount of computer memory is essential, as unlike earlier times, our memory needs have grown. Normally, we have an email client, messenger, and music already running when we sit down to work on our computers. All of these have taken their share of memory already, leaving little behind for the application we want to launch for our work. These days 512 MB RAM is the recommended norm.