Dual Inline Memory Module (DIMM)

A dual inline memory module, or DIMM, is the standard form factor for memory modules in servers, workstations and PCs. The name refers to the independently assigned contact rows on both sides of the circuit board, which provide a wider data connection than older SIMM modules. DIMMs are installed in the memory banks of the mainboard and, depending on the platform, arranged in channels for dual, quad or octa channel operation. Modules are differentiated by memory generation such as DDR3, DDR4 and DDR5, and by type, including UDIMM for desktops, registered RDIMM and LRDIMM for servers, and SO-DIMM for laptops. Server environments commonly use ECC modules that detect and correct bit errors. Key selection criteria include mainboard compatibility, clock frequency, rank structure and the maximum supported capacity.