Dual inline memory module
As dual inline memory module ( DIMM , English about double row memory module ) are memory modules in the memory of computers , respectively. In contrast to single inline memory modules (SIMM), DIMMs carry different signals on the connection contacts on the front and rear of the circuit board , usually because there are memory modules on both sides of the circuit board .
DIMMs are now known in a large number of designs. The more common are:
- DIMMs with 168 contacts and two notches in the contact strip are usually equipped with SDRAM and have a 64-bit data bus. The exact position of the notch between contacts 40 and 41 is varied again in the sub-versions of this design and is used to identify the intended voltage supply for the module. Positioned more on the left: 5 V, positioned in the middle: 3.3 V, positioned on the right: reserved for special cases. The exact position of the notch between contacts 10 and 11 also varies. More rarely there are modules that are equipped with EDO , as well as SRAMs for use as L2 cache . To avoid confusion, they are distinguished by the slightly different positions of these two notches.
- Dual Inline Modules with 184 contacts and one notch are equipped with DDR-SDRAM .
- Dual Inline Modules with 240 contacts and one notch are equipped with DDR2 SDRAM chips or DDR3 SDRAM chips.
- Dual Inline Modules with 288 contacts and one notch are equipped with DDR4 SDRAM .
- Dual Inline Modules with 72 or 144 contacts (SDRAM), 200 contacts (DDR and DDR2 RAM), 204 contacts (DDR3 RAM) or 260 contacts (DDR4 RAM) are used in laptops as SO-DIMMs .
Other designs are also used for special server applications.
In contrast to SIMM modules, which are inserted into their sockets at a slight angle without the use of force and fixed by being folded up using a spring latch (or sometimes inserted vertically and their end position is inclined), DIMM modules, with the exception of SO-DIMMs, are always perpendicular to the motherboard pressed in, using small levers at the ends of the base to help with removal.
There is also so-called NV-DIMM (or NVDIMM ), which probably stands for Non-Volatile Dual Inline Memory Module ( i.e. non- volatile [working] memory ).
