As the years go by, the manufacturing technology of memory sticks is also constantly improving, and the "dynasties" of DDR/DDR2/DDR3 memory sticks are also changing with new and old ones, and this process is not over. The existing DDR4 and DDR5 memory sticks are also Conditions for popularization are constantly being created. If you don’t understand how to distinguish DDR1/DDR2/DDR3 memory sticks, you can read below to learn about the differences between DDR, DDR2 and DDR3 and how to distinguish them.

Technology is advancing, and of course the production technology of memory modules is also developing, which has led to the emergence of DDR1, DDR2, and DDR3 memory modules. The differences between generations are as follows:

Appearance differences between DDR 1, 2, and 3 generations of memory

DDR1:

There is a notch, 92 pins on one side, 184 pins on both sides, 52 on the left and 40 on the right, and the memory particles are rectangular.

DDR2:

One notch, 120 pins on one side, 240 pins on both sides, 64 on the left and 56 on the right, square memory chips, voltage 1.8V.

DDR3:

One notch, 120 pins on one side, 240 pins on both sides, 72 on the left and 48 on the right, square memory chips, voltage 1.5V.

Its operating voltage has been decreasing, so while performance is improving, power consumption is also gradually becoming smaller.

As for the slots on the motherboard, the three are different. There is a small gap on the memory interface. The interfaces of each type of DDR, DDR2, and DDR3 memory are not in the same position, so you can only plug them in. You must check first when purchasing. Buy the memory according to what kind of memory the slots on the motherboard support. And these three types of memory sticks are not compatible.

The difference in memory capacity between DDR DDR2 and DDR3

Who doesn’t have a 2G home computer nowadays? 8G and above are not uncommon, right? The minimum requirement for some gamers is 4G, right? If this happened in 2000, who would believe it?

The smallest memory of DDR1 is only 64M and the largest one only has a capacity of 1G. The smallest memory of the second generation DDR is 256M and the largest one is already 4M. Of course, few people use DDR2 4G, and the most common ones are 1Gx2. The smallest DDR3 is now 512M and the largest is 8G. Generally, 4Gx2 is used in this way. Or use 2Gx2 like this.

DDR DDR2 DDR3 Differences in packaging

The early DDR sealed particles were TSOP, and starting from DDR2 and DDR3, FBGA packaging was used. DDR2 used an 8-bit chip using 60-ball/68-ball/84-ball FBGA packaging in three specifications, while DDR3 used a 16-bit chip using 96 balls. FBGA package, and DDR3 must be a green package and cannot contain any harmful substances.

The reference voltage is divided into two. In the DDR3 system, the reference voltage signal VREF, which is very important for the operation of the memory system, will be divided into two signals, namely VREFCA, which serves the command and address signals, and VREFDQ, which serves the data bus. This will effectively improve The signal-to-noise level of the system data bus.

DDR DDR2 DDR3 in burst length (BurstLength, BL)

Since the prefetch of DDR3 is 8 bits, the burst transmission period (BurstLength, BL) is also fixed at 8, while the transmission period of DDR is 2 and DDR2 is 4.

DDR DDR2 DDR3 Differences in the number of logical banks

There are 2 Banks and 4 Banks in DDR. DDR2 has 4 Banks and 8 Banks. By the time of DDR3, there were already 8 Banks and 16 Banks. At present, it is to meet the requirements of future large-capacity chips, and DDR3 is likely to start from 2G, so there are 8 logical banks, and it is also prepared for 16 logical banks in the future.

DDR DDR2 DDR3 addressing timing difference (Timing)

The number of latency cycles has been increasing from the first generation of DDR to the second generation and then to the third generation of OnePlus memory. The CL cycle of the third generation of memory will also be correspondingly higher than that of the second generation of memory. The CL range of second-generation memory is generally between 2 and 5, while the second-generation memory has increased to between 5 and 11, and the design of third-generation memory latency (AL) has also changed. The range of AL is 0 to 4 for second-generation memory, while AL has three options for third-generation memory, namely 0, CL-1 and CL-2. In addition, the third generation of memory also adds a new timing parameter - write delay.

Compared with DDR DDR2, new functions of DDR3

DDR has a new reset function. The newly added reset is an important function of DDR3, and a pin is specially prepared for this function. This pin will make the initialization process of DDR3 easy. When the Reset command is valid, DDR3 memory will stop all operations and switch to a minimum amount of activity to save power.

DDR3 has a new ZQ calibration function. ZQ is also a new pin. A 240 ohm low-tolerance reference resistor is connected to this pin. This pin uses a command set to automatically verify the data output driver on-resistance and ODT termination resistance value through the on-chip calibration engine (On-DieCalibrationEngine, ODCE). When the system issues this instruction, it will use the corresponding clock cycles (512 clock cycles after power-on and initialization, 256 clock cycles after exiting the self-refresh operation, and 64 clock cycles in other cases). On-resistance and ODT resistance are recalibrated.

The above is about the differences and identification methods between DDR, DDR2 and DDR3. Of course, if users do not have actual measurement tools, they can use third-party software for detection, but the detection information is not absolutely correct.