Difference between DDR3 and DDR4- How to differentiate DDR3 DDR4 RAM memory

In the past two years, DDR4 memory has been dominating the market, with a massive influx of DDR4 products and a rapid increase in market share. However, DDR3 still holds a significant portion of the market. Many users are unsure about how to choose when buying memory, as the prices of both, with the same capacity, are not significantly different. So, what are the main differences between the two?

Appearance In terms of appearance, there is not much difference between the two. Generally, the only way to distinguish them is through the information on the labels and the different slot positions.

Regarding the slots, DDR4, compared to DDR3, has the notch position closer to the center. For desktop memory, the number of gold finger contacts increased from 240 to 284, and the spacing between contacts decreased from 1mm to 0.85mm. The specific design changes were made to facilitate the insertion and removal of memory modules. However, the height increase is slight and does not affect usability.

Another significant feature is the change in the horizontal direction of the gold fingers of desktop DDR4 memory. Instead of a straight line, it is slightly curved, with the middle being slightly longer and the ends slightly shorter. This design aims to make it more convenient to insert and remove memory modules. However, laptop memory gold fingers do not have this design since laptop memory is rarely inserted or removed.
Capacity In terms of capacity, the standard specifications for DDR3 and DDR4 generations are 4GB and 8GB, 8GB and 16GB, respectively.

3-Dimensional Stack (3DS) technology is one of the key technologies in DDR4 memory, increasing the capacity of a single chip. Theoretically, a single module can reach up to 128GB, although this hasn't been implemented in consumer-grade products. Larger capacities come with higher prices, making them less affordable for average consumers. Currently, 8GB and 16GB capacities are the most common in the market, and 4GB DDR3 memory is gradually exiting the market.
Frequency Frequency has always been one of the crucial parameters for memory products. When choosing memory, users typically look at capacity first and then consider frequency since it directly affects performance. DDR3 frequencies, such as 800, 1066, 1333, 1600, 1866, 2133, and 2400, have been familiar to us over the past decade. DDR3 memory has accompanied us for nearly 10 years, with 2133 and 2400 being more common in overclocking.

As for DDR4 memory, it starts with a frequency of 2133, and common frequencies include 2133, 2400, 2666, 2800, 3000, and 3200. Mainstream consumer-level frequencies are concentrated around 2133 and 2400, with 3000 and higher primarily existing in the overclocking domain, beyond the needs of daily use.
Voltage In terms of voltage, there has been a continuous decrease in memory product voltages. The common operating voltages are as follows:

DDR3: 1.5V
DDR3L: 1.35V/1.28V
DDR3U: 1.25V
DDR4: 1.2V
The history of memory development is essentially a history of voltage reduction, from DDR's 2.5V to DDR2's 1.8V, then DDR3's 1.5V, and finally to DDR4's 1.2V. It remains to be seen whether a low-voltage version of DDR4 will emerge, and the voltage specifications for DDR5 are unknown after its introduction.