Difference between laptop and desktop about ram

Difference between laptop and desktop about ram

All PCs use RAM (Random Access Memory) to operate. Desktop PCs generally support larger capacities of RAM than their laptop counterparts. Even if the capacity or speed of RAM is the same, the RAM modules installed on desktop and laptop PCs are very different.

Physical Limits

Desktop RAM modules conform to a standard size and shape, where one RAM module may be installed in any desktop PC, provided it is a compatible standard. Some laptop RAM modules are tailored to a specific make and/or model, where the module must be able to fit within a special compartment inside the laptop, as well as match the manufacturer's technical specifications.

RAM Standards

Desktop PC RAM standards have evolved since the early 1980s; commonly known as SIMM, DIMM, SDRAM, DDR, DDR2 and most recently DDR3. Laptop RAM shares some of these standards, but in a form known as SO-DIMM, which is designed to be more compact. However, exact compatibility of SO-DIMM modules varies from one manufacturer to the next.

History

Early models of laptop PCs were often limited to proprietary RAM modules, designed and/or made by the laptop manufacturer. They were more expensive and came in smaller capacities than desktop RAM modules. With the development of the compact SO-DIMM standard, laptop manufacturers adopted it over the older proprietary forms, and the capacity evolved to become competitive with desktop PC RAM. SO-DIMM modules have also been adopted for use in many printers, enterprise networking technology and small-form-factor PCs.

Total RAM Modules

Even the most advanced laptop PCs feature only one or two additional RAM modules, where some RAM may have been permanently installed at the factory and cannot be replaced. Desktop PCs typically support anywhere from two to six RAM modules at once, where all modules can be replaced or upgraded.

RAM Capacity Timeline

In the mid 1980s, PC RAM modules (or SIMMs) were available in 1-, 2- and 4-megabyte capacities. By the end of 2008, RAM modules of 1, 2 or 4 gigabytes each were commonplace on desktop PCs, and up to 2 gigabytes each on laptops/notebooks (1 gigabyte = 1,024 megabytes).

SO-DIMM Types

There are four common types of SO-DIMM modules: 72-pin, 100-pin, 144-pin and 200-pin. While the speed and capacity of the module is not necessarily limited by the number of pins, it is a critical factor in determining whether a SO-DIMM module is compatible with your device.