Identifying the Random Access Memory is not difficult. In general, there are three common types: DDR1, DDR2, and DDR3. To identify them physically is not difficult. You simply need to define the distance of Notch, as well as the intergrated chip (IC) type. But first, you need to confirm that is indeed DDR1, DDR2, or DDR3 and not one of the SDRAM. Keep the chip’s front facing you and look at the DDR Notch. The notch will vary in the DRR.
Distance of Notch
The notch is a small cut on the RAM itself. In all DDR, the notch is at the base of the RAM. In DDR1 and DDR2, the notch cuts look similar. However, in DDR1, the notch is just above the IC while in DDR2, the notch is a bit farther from the IC. In DDR3, the notch is nowhere near the center.
The Integrated Chip
In DDR3, the IC is small and square. In DDR2, it is bigger which DDR1 has the largest IC. In DDR1, the IC touches the bottom and top while in DDR2, it is just inside the borders. In DDR3, the IC is quite small and nowhere close to the edge.
The Pin Count in DDR1, DDR2, DDR3 are as follow:
• DDR1 – 184 Pins
• DDR2 – 240 Pins
• DDR3 -240 Pins
The voltage of the RAM
The voltage is not used to physically identify the RAM. However, it can be used to find the right motherboard slot. The voltage is indicated in the motherboard slot.
• DDR1 Volts – 2.5 V
• DDR2 VoIts – 1.8 V
• DDR3 Volts – 1.5 V
Comparing DDR2 and DDR3
A modern laptop uses either DDR2 or DDR3. The DDR3 was introduced in 2008 when Intel released the Core i7 first generation processors. After that, most of the industry moved to DDR3, although there are still DDR2 users. All new processors created by Intel since they can only work with a motherboard that uses DDR3 and not any lower than that. Even AMD motherboards have been switching to DDR3.
DDR stands for Double Data Rate RAM. It came about at the turn of the century when the first Double Data Rate RAM was used. It is able to conduct two data transfers in each clock cycle. Thus, it theoretically has twice the peak bandwidth compared to the previous SDRAM without an increase in clock speed.
How do DDR2 and DDR3 Defer?
Both of these are improvements on the same technology. There has also been an increase in the number of data transfers for each clock cycle. DDR2 is capable of 4 data transfers in a clock cycle while DDR3 doubles that to 8. Assuming that there is a base clock speed of 100MHz, the DDR1 RAM will offer 1600 MB/s of bandwidth while DDR2 will offer 3200 MB/s. DDR3 will then be offered 6400MB/s.
The Performance Issues
In practice, you will not notice a major difference between the DDR2 and DDR3. While the increase memory bandwidth is awesome, about 99% of all programs cannot create a large enough workload that is restricted by memory bandwidth. This issue is only important to workstation and server class products. There are benchmark programs that can test the memory bandwidth.
When purchasing DDR2 or DDR3, it is not about preference. In fact, these two are not compatible. If you have a motherboard that uses DDR2, it cannot be upgraded to DDR3. You would also need to change the motherboard. Thus, if you have a working computer using DDR2 RAM, you need to throw out a working motherboard and the DDR2 RAM just to use DDR3 RAM.
There are some motherboards, which are exempted from this rule. However, this is only because they have slots for bother DDR2 and DDR3. These can only be found in only the older chipsets. While it is a letdown, you can do little about it. Both AMD and Intel have commuted to only use DDR3 or higher in the future. This means that you might have to upgrade your computer to avoid using a dinosaur.
The Clock Speed
Clock speed is quite important when looking into RAM. Clock speed tells you how well RAM is going to perform. It works, in the same way, as to how a clock speed shows you how well a processor is doing. It is part of an equation, which will determine the maximum peak bandwidth of the memory. Higher clock speed is important. However, this will likely not matter in everyday use.
It is important to know that some motherboards will only accept memory in a limited range of clock speed. Thus, always visit the site of the manufacturer to check if RAM is compatible. Motherboards are flexible but it is always good to be on the safe side.
The invention of DDR3 effectively made DDR2 obsolete. In short, if you have RAM below DDR3, it is a good idea to upgrade, even a personal computer. Soon, you might face huge challenges when using your desktop computer.