Main Memory - Compaq Evo D310 Micro-Desktop Technical Reference Manual

Main Memory

Short for Double Data Rate-Synchronous DRAM, DDR-SDRAM is a type of SDRAM that supports data
transfers on both edges of each clock cycle, effectively doubling the memory chip's data throughput.
DDR-SDRAM also consumes less power. DDR-SDRAM is also called SDRAM II.
While the new memory module is clocked at the same speed as normal SDRAM, it is able to transport
double the amount of data by using the rising as well as falling edge of the clock signal for data transfers.
DDR-SDRAM has another important enhancement over SDRAM. Its voltage supply uses only 2.5 V,
instead of 3.3 V. This and the lower capacities inside the memory chips lead to significantly reduced
power consumption.
DDR-SDRAM DIMMs are not compatible with SDRAM DIMMs . The new DDR-DIMMs come with 184
instead of the 168 pins used by SDRAM-DIMMs. The module itself looks almost identical to SDRAM, but
it has only one notch on its connector surface instead of the two notches found on SDRAM-DIMMs.
There are two memory module slots on the system board for installing main
DIMM slots
memory. You can install 266MHz DDR-SDRAM modules, these are available in
128, 256 and 512MB memory modules. You can install a maximum of 1GB
(2 x 512MB modules).
You can only use non-ECC memory modules.
System Features
Evo D310 Micro Desktop 21