Memory

As with desktop systems, adding memory is one of the most common upgrades to portable computers. Unlike desktop computers, which offer only three basic types of slots for additional RAM (random access memory), there are dozens of different memory-chip configurations designed to squeeze memory upgrades into the small cases of portable systems.

Some portables use memory cartridges that look a lot like PC Cards, but they plug into a dedicated IC memory socket. Others use extender boards like SIMMs (single inline memory modules) and DIMMs (dual inline memory modules). In any case, it is strongly recommended that you only install memory modules that have been designed for your system, and only in the configurations recommended by the manufacturer. This does not necessarily limit you to products made by your system's manufacturer, however, because a number of companies manufacture upgrade modules for dozens of systems.

Portable computers use the same types of dynamic RAM (DRAM) and static RAM (SRAM) as desktops and, thanks to advances in thermal management, today's high-end portable systems usually include SRAM cache memory.