Below is a small table indicating the Evolution of Memory.
| Year Introduced | Technology | Speed Limit | Form Factor |
| 1987 | FPM | 50ns | 30- or 72-pin SIMM |
| 1995 | EDO | 50ns | 72-pin or 168-pin DIMM |
| 1996 | PC66 SDRAM | 66MHz | 168-pin DIMM |
| 1998 | PC100 SDRAM | 100MHz | 168-pin DIMM |
| 1999 | RDRAM | 800MHz | 184-Pin RIMM |
| 1999/2000 | PC133 SDRAM | 133MHz | 168-pin DIMM |
| 2000 | DDR SDRAM | 266MHz | 184-pin DIMM |
