DIMM MEMORY SLOTS

A DIMM or dual in-line memory module, comprises a series of dynamic random-access memory integrated circuits. These modules are mounted on a printed circuit board and designed for use in personal computers, workstations and servers. DIMMs began to replace SIMMs (single in-line memory modules) as the predominant type of memory module as Intel P5-based Pentium processors began to gain market share.
The main difference between SIMMs and DIMMs is that DIMMs have separate electrical contacts on each side of the module, while the contacts on SIMMs on both sides are redundant. Another difference is that standard SIMMs have a 32-bit data path, while standard DIMMs have a 64-bit data path. Since Intel's Pentium has (as do several other processors) a 64-bit bus width, it requires SIMMs installed in matched pairs in order to complete the data bus. The processor would then access the two SIMMs simultaneously. DIMMs were introduced to eliminate this practice.
The most common types of DIMMs are:
72-pin SO-DIMM (not the same as a 72-pin SIMM), used for FPM DRAM and EDO DRAM
100-pin DIMM, used for printer SDRAM
144-pin SO-DIMM, used for SDR SDRAM
168-pin DIMM, used for SDR SDRAM (less frequently for FPM/EDO DRAM in workstations/servers)
172-pin MicroDIMM, used for DDR SDRAM
184-pin DIMM, used for DDR SDRAM
200-pin SO-DIMM, used for DDR SDRAM and DDR2 SDRAM
204-pin SO-DIMM, used for DDR3 SDRAM
214-pin MicroDIMM, used for DDR2 SDRAM
240-pin DIMM, used for DDR2 SDRAM, DDR3 SDRAM and FB-DIMM DRAM
244-pin MiniDIMM, used for DDR2 SDRAM