Side-by-Side Comparison
RAM
DDR vs. DDR3
Comparing 2 standards across 5 specifications. 5 key differences identified.
Comparing:
DDR
DDR3
DDR SDRAM (sometimes called DDR1), finalized by JEDEC in 2000, was the first double-data-rate memory standard -- transferring data on both the rising and falling edge of the clock signal. It used a 184-pin DIMM for desktops and a 200-pin SO-DIMM for laptops, running at 2.5V.
DDR3, standardized in 2007, kept DDR2's 240-pin DIMM count but switched from a rounded to a square notch in a different position, making the two physically incompatible despite the matching pin count. It dropped voltage to 1.5V (1.35V for the low-power DDR3L variant) and raised data rates up to DDR3-2133.
Specification Comparison Table
5 Parameters| Parameter / Spec | ||
|---|---|---|
|
JEDEC Standard
|
2000 (JESD79) | 2007 |
|
DIMM Pins
|
184 | 240 (same count as DDR2; different notch shape and position -- not compatible) |
|
SO-DIMM Pins
|
200 | 204 |
|
Nominal Operating Voltage
|
2.5 (2.6V for DDR-400) V | 1.5 (1.35V for DDR3L low-voltage variant) V |
|
Data Rate Range
|
200–400 (DDR-200 to DDR-400) MT/s | 800–2133 (DDR3-800 to DDR3-2133) MT/s |