DDR2 vs. DDR4
Comparing 2 standards across 5 specifications. 5 key differences identified.
DDR2, standardized by JEDEC in September 2003, doubled DDR's internal prefetch to 4 bits and dropped operating voltage to 1.8V. Its 240-pin DIMM introduced a new pin count, but its 200-pin SO-DIMM confusingly matches DDR1's pin count -- the two are still incompatible via a different notch position.
DDR4's spec was finalized in September 2012, though it didn't reach the commercial market until 2014. It moved to a 288-pin DIMM and 260-pin SO-DIMM, dropped voltage to 1.2V, and started at a minimum of 2133 MT/s -- roughly double DDR3's starting point.
Specification Comparison Table
5 Parameters| Parameter / Spec | ||
|---|---|---|
|
JEDEC Standard
|
September 2003 | September 2012 (spec); 2014 (commercial market) |
|
DIMM Pins
|
240 | 288 |
|
SO-DIMM Pins
|
200 (same count as DDR1, different notch position -- not compatible) | 260 |
|
Nominal Operating Voltage
|
1.8 V | 1.2 V |
|
Data Rate Range
|
400–1066 (DDR2-400 to DDR2-1066) MT/s | 1600–3200 (JEDEC); commercially up to ~4800 overclocked MT/s |