Short for dual in-line memory module, DIMM is a module containing a circuit board and one more random access memory chips. DIMMs have a 168-pin connector and, from the advent of the Pentium processor, a 64-bit path. Because of the new bit path, DIMMs can be installed one at a time, unlike SIMMs that would require installation in pairs.
SO-DIMM, which is short for small outline dual in-line memory module, is available in both a 72-pin and 144-pin configuration. SO-DIMMs are commonly utilized in laptop computers. Below is an example picture of a 4 GB SODIMM memory stick from Crucial.
Some of the advantages DIMMs have over SIMMs
DIMM sizes vary from micro ATX to standard motherboards so no. Of pins is an important factor. While purchasing a RAM stick, ratings are like 16 GB RAM can be 1X16GB (1 DIMM and 16 GB RAM each), 2X8GB (2 DIMM and 8 GB RAM each) or 4X4GB (4 DIMM and 4 GB RAM each). The pins on the bottom of each RAM stick are notched, which means the RAM modules can only be inserted into the DIMM slot one way. Also, if you're using two RAM modules at once, you want to make sure they're inserted into matching DIMM slots on your motherboard (these slots are usually color-coded and oftentimes not right next to each other). DIMMs are being installed per CPU on a DL385, they should be located in white DIMM slots numbered 16 and 14. If six DIMMs are being used per CPU, they should be installed in DIMM slots 16, 14, 12, 10, 3, and 1. Nov 14, 2017 Matched DIMM configuration in each channel. Matched in symmetrical memory slots. Configurations that do not match the above conditions revert to single-channel mode. The following conditions do not need to be met: Same brand; Same timing specifications; Same speed (MHz) The slowest DIMM module populated in the system decides memory channel speed. A DDR2 SDRAM DIMM will not fit into a standard SDRAM DIMM socket or a DDR DIMM socket. DDR2 modules use a 1.8V power supply, providing a big power saving over the 2.5V DDR modules. To use DDR3 memory, your system motherboard must have 240-pin DIMM slots and a DDR3-enabled chipset.
- DIMMs have separate contacts on each side of the board, which provides twice as much data as a single SIMM.
- The command address and control signals are buffered on the DIMMs. With heavy memory requirements, this buffering reduces the loading effort of the memory.
Related pages
Computer acronyms, Connector, Hardware terms, Memory terms, Pentium processor, SATADIMM
Before understanding about DIMM, it is good to have information regarding RAMs and its accessories and how it operates.
A RAM is a chip made up of several electronic elements that store the temporary working data of your system which can be read and written. RAM requires electric supply for functioning, hence when the system is turned off, all data from RAM vanishes. It is mounted on the motherboard.
The RAM chips are not individually mounted on the motherboard because of less capacity, hence in earlier times, several chips used to be soldered together and converted into 'modules'(integrated circuit boards) and these modules were mounted over motherboard using 'pins'(also known as connectors).
Types of modules
There are two types of modules in a RAM:
- Single In-line Memory Module(SIMM)
- Dual In-line Memory Module(DIMM)
In the case of SIMM, the connectors are only present on the single side of the module and are shorted together. SIMMs are always used in matched-pairs. The maximum data storage offered by SIMM is 32-bit/cycle and voltage consumption is 5 volts.
As technology evolved, SIMM became obsolete and was replaced by DIMM. DIMM has the row of connectors on both the sides(front and back) of the module and connectors are independent. This resulted in twice the capacity of DIMM with the same quantity of RAM hence supporting the 64-bit processors. While two SIMM sticks would be used in parallel for 64-bit data width (which is a disadvantage!). The voltage consumption of DIMM is 3.3 volts which are comparatively lower. It is not backward compatible i.e it cannot be used on motherboards having SIMM slots. It is easier to replace damaged or corrupted RAM piece on DIMM.
This proves that DIMM cleary outperforms SIMM in speed, latency, and power consumption. El casino stuffed flounder. DIMM is generally available in 168, 184, 214 or 244 pins.
Classification of DIMM
DIMM can be classified on the basis of buffer size and type of RAM:
- DIMM classification based on buffer size:
- Unbuffered DIMM (UDIMM): The system directly reads/writes from/to memory chip without validation hence increasing the electrical load on the motherboard but are very faster.
- Registered DIMM (RDIMM): uses register that buffers signals, hence increasing clock cycle but are more reliable.
- DIMM classification based on the type of RAM:
- SDRAM (synchronous dynamic RAM) DIMM: It was the first dynamic RAM to sync with the system clock. The refresh rate was much lower due to re-accessing data after the rising half cycle.
- SDR(single data rate) DIMM: single data rate means the packet of data is only accessed once per clock cycle. Serial data can be read via the serial data pins on the DIMM which enables the motherboard to autoconfigure to the exact type of DIMM installed.
- DDR(double data rate) DIMM: Data packet is accessed twice each clock cycle. DDR DIMMs also use two notches on each side to enable compatibility with both low- and high-profile latched sockets.
- DDR2 DIMM: The key difference between DDR and DDR2 is that in DDR2 the bus is clocked at twice the speed of the memory cells, so data can be transferred four times faster per memory cell cycle.
DDR3 and DDR4 are the improvised versions of DDR with less latency and better accuracy. SODIMM (small outline DIMM) is much more compressed with noticeable size-reduction to use it in portable devices.
How to select proper DIMM?
DIMM sizes vary from micro ATX to standard motherboards so no. of pins is an important factor. While purchasing a RAM stick, ratings are like 16 GB RAM can be 1X16GB(1 DIMM and 16 GB RAM each), 2X8GB(2 DIMM and 8 GB RAM each) or 4X4GB(4 DIMM and 4 GB RAM each). Operating frequency and maximum overclocking frequency should also be taken into consideration.
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