DDR2 DIMM also uses 240 pins but is physically incompatible with DDR3. DDR2 operates at 1.8V with speeds from DDR2-400 to DDR2-1066. Used in PCs from 2004 to 2010.
| Pin | Name | Function | Type |
|---|---|---|---|
| 1 | VSS | Ground | GND |
| 2 | DQ0 | Data bit 0 | I/O |
| 5 | DQS0+ | Data strobe 0 positive | I/O |
| 240 | VSS | Ground | GND |