SDRAM has 168 pins and two notches on the module.
DIMMs have 168, 184, or 240 pins on the edge connector of the board and can hold from 8MB to 2GB of RAM. Info from my A+ book.
Types of DIMMs are DDR3 and DDR2 that have 240 pins, DDR DIMMs with 184 pins and SDRAM DIMMs with 168 pins.
DIMM. Two types of DIMMs: a 168-pin SDRAM module (top) and a 184-pin DDR SDRAM module (bottom). Note that the SDRAM module has two notches (rectangular cuts or incisions) on the bottom edge, while the DDR1 SDRAM module has only one.
The EDO RAM desktop memory modules have 72 pins and operate at 5V as standard
168 pins are used on SDRAM DIMM. 184 pins are used on DDR DIMM. There are either 30 pins or 72 pins used on SIMM. 184 pins are used on RIMM.
168
This is some specification for RAM modules: DDR3 240-pin DDR 2 240Pin DDR 184 Pin SDRAM 168-pin SODIMM 200-pin DDR2 SODIMM 200-pin DDR,DDR2 and DDR3 have 2 holes SDRAM have 3 holes
168
A duel inline memory module (DIMM) is an advanced version of randome access memory (RAM) that came after the singe inline memory module (SIMM) that runs on 168, 184, or 240 pins.
168-pin SDRAM DIMM
DDR
168-pin SDRAM168-pin DIMM30 or 72-pin SIMM 184, 168 or 232-pin RIMM