Desktop memory is a form of RAM (random-access memory) used on a desktop computer. The memory allows for storage of data which can be retrieved more quickly than if it were stored on a device such as a hard drive or DVD. Therefore, when a program or system process is running on a PC, it can use the memory to be loaded and accessed more speedily.
Types
Desktop memory is available in a wide variety of types. One of the most common major types is SDRAM (synchronous dynamic random access memory). Under this form are types such as DDR, DDR2, DDR3, and the currently being prepared DDR4. Read more details about particular types.
Even within each subtype, for instance DDR2, there are numerous options. For example, within this type of desktop memory are chips such as DDR2-667 (also known as PC2-5300), DDR2-800 (PC2-6400), and others. Once you consider other pieces of information such as the memory timings (CAS latency) and capacity (GB or MB), as well as the other forms of memory, there are hundreds of options for desktop memory. This is even before thinking of the different manufacturers and the available brands and models.
How much desktop memory is needed?
Different machines and the individuals using them will require various amounts of memory for either sufficient or preferred quality of computer performance. In recent years, amounts of 1 GB or above have become common, and now many computers are shipped with 2 to 4 GB of RAM. This is quite sufficient for many individual users, although operating systems and programs running may need to be taken into consideration. Computers which will be used as servers, or for memory-intensive tasks, may be better-equipped with greater amounts of desktop memory.
Consider reading about virtual memory.
What is the limit on desktop memory in a PC?
Due to limitations of 32-bit computing, such operating systems are only able to register roughly 4 GB of memory. In some situations, such as 32-bit Windows, technical reasons make the maximum amount of usable memory closer to 3.2 GB. In 64-bit operating systems, the limit is much higher (beyond what any individual user would realistically use with today's applications). However, some 64-bit applications place artificial limits on the amount of desktop memory that can be used. 64 GB or 128 GB are some possibilities - some go beyond 1 TB (which is 1000 GB).