Evolution of Memory

• 1970: RAM /DRAM, 4.77 MHz
                     
• 1987: FPM - fast page mode DRAM, 20 MHz
                          
• 1995, EDO - Extended Data Output, which increases the read cycle between memory and CPU, 20 MHz
                          
• 1997- 1998: SDRAM - Synchronous DRAM, which synchronizes itself with the CPU bus and runs at higher clock speeds, PC66 at 66 MHz, PC100 at 100 MHz
                        
• 1999: RDRAM - Rambus DRAM, which DRAM with a very high bandwidth, 800 MHz
                         
• 1999-2000: SDRAM - PC133 at 133 MHz, DDR at 266 MHz.
                               
• 2001: EDRAM - Enhanced DRAM, which is dynamic or power-refreshed RAM, also know as cached DRAM.