Double Data Rate (DDR), also known as DDR1, is the second generation of Synchronous DRAM (SDRAM). As its name implies, double data rate refers to its ability to read and write data on both the rising and falling of the system clock to achieve nearly twice the bandwidth of single data rate (SDR) SDRAM.
JEDEC developed the DDR SDRAM specification (JESD79) in 2000 and was an advancement over SDRAM technology with increased memory bandwidth and performance. ATP DDR1 modules have 400 MT/s transfer speeds and run at 2.5V, significantly cutting power consumption compared with SDRAM's 3.3V.
|DIMM Type||ECC UDIMM||Non-ECC UDIMM||ECC SO-DIMM||Non-ECC SO-DIMM|
|Density||512 MB||256 MB||256 MB to 512 MB / 1 GB||128 MB to 512 MB / 1 GB|
|Speed up to (MT/s)||400||400||400||400|
|PCB Height||Low Profile||Low Profile||Low Profile||Low Profile|
|Operating Temperature||0°C to 85°C||0°C to 85°C||0°C to 85°C||0°C to 85°C / -40°C to 95°C|