DDR2: memory for laptop, computer. Overview, specifications, prices, features

The component market is constantly replenished with new developments and innovations with enviable regularity, which is why many users, whose means obviously do not allow getting new hardware in a timely manner, have doubts about the power and performance of their computer as a whole. At all times, a discussion of a lot of questions on technical forums about the relevance of their components never subsides. At the same time, questions concern not only the processor, the video card, but even the RAM. However, even despite the entire dynamics of computer hardware, the relevance of technology of previous generations is not lost as quickly. This also applies to the components of RAM.

DDR2-memory: from the first days on the market to sunset popularity

DDR2 is the second generation of random access memory (SDRAM), or, in the wording familiar to any user, the next generation of random access memory after DDR1, which is widely used in the personal computer segment.

Being developed back in 2003, the new type could fully gain a foothold in the market only by the end of 2004 - only at that time chipsets with DDR2 support appeared. Actively advertised by marketers, the second generation was presented as an almost twice as powerful alternative.

What should be primarily distinguished from the differences is the ability to operate at a significantly higher frequency, transmitting data twice in a single clock cycle. On the other hand, the standard negative point of raising frequencies is to increase the delay time during operation.

Finally, by the mid-2000s, the new type had fundamentally infringed on the positions of the previous, first, and only by 2010 was DDR2 significantly replaced by the new DDR3 that came to replace it.

Device features

Distributed RAM modules DDR2 (in everyday speech called “dice”) had some distinctive features and varieties. And although the new type of memory for its time did not openly amaze with the abundance of variations, even external differences were immediately evident to any buyer at first sight:

• Single-sided / double-sided strip module SDRAM, on which microcircuits are located on one or two sides, respectively.
• DIMM is today's standard form factor for SDRAM (synchronous dynamic random access memory, of which DDR2 is). Mass use in general-purpose computers began as early as the end of the 90s, which was mainly promoted by the appearance of the Pentium II processor.
• SO-DIMM is a shortened form factor for the SDRAM module, designed specifically for laptop computers. The SO-DIMM DDR2 dice for a laptop had several significant differences from standard DIMMs. This is a module with smaller physical dimensions, lower power consumption and, as a result, a lower level of performance compared to the standard DIMM factor. An example of a DDR2 RAM module for a laptop can be seen in the photo below.

In addition to all the above features, it should also be noted a rather mediocre "shell" of the dies of those times - almost all of them, with rare exceptions, were then represented only by standard boards with microcircuits. Marketing in the computer hardware segment was just starting to spin up, so there were simply no samples with radiators of various sizes and designs that were already familiar to modern RAM modules. Until now, they perform primarily a decorative function, rather than the task of removing the heat generated (which, in principle, is not characteristic of random access memory like DDR).

In the photo below, you can see how the DDR2-667 RAM modules look like with a radiator.

Compatibility key

DDR2-memory in its design has an extremely important difference from the previous DDR - the lack of backward compatibility. In the second-generation samples, the slot in the contact zone of the bracket with the RAM connector on the motherboard was already located differently, which is why it is physically impossible to insert the DDR2 card into the DDR-based connector without breaking one of the components.

Volume parameter

For serial motherboards (any motherboard for home / office use), the DDR2 standard could offer a maximum capacity of 16 gigabytes. For server solutions, the volume limit reached 32 gigabytes.

It is also worth paying attention to one more technical nuance: the minimum volume of one die is 1 GB. In addition, there are two more options for DDR2 modules on the market: 2Gb and 8Gb. Thus, in order to get the maximum possible supply of RAM of this standard, the user will have to install two 8 GB strips or four 4 GB strips, respectively.

Data rate

This parameter is responsible for the ability of the memory bus to pass as much information as possible per unit of time. The higher the frequency value, the more data it will be possible to betray, and here the DDR2 memory significantly outstrips the previous generation, which could operate in the range from 200 to 533 MHz maximum. After all, the minimum frequency of the DDR2 bar is 533 MHz, and the top-end models, in turn, could boast overclocking to 1200 MHz.

However, with increasing memory frequency, timings also naturally rose, on which the memory performance depends not least.

About timings

Timing is the time interval from the moment of requesting data to reading them from the main memory. And the more the module frequency increased, the longer it took the RAM time to complete operations (not to enormous delays, of course).

The parameter is measured in nanoseconds. The most affecting performance is latency timing (CAS latency), which is referred to in the specifications as CL * (any number can be indicated instead of *, and the smaller it is, the faster the memory bus will work). In some cases, the timings of the slats are indicated by a three-character combination (for example, 5-5-5), however, the first number will be the most critical parameter - it always indicates the latency of the memory. If the timings are indicated in a four-digit combination, in which the last value is strikingly greater than all the others (for example, 5-5-5-15), then this indicates the duration of the total working cycle in nanoseconds.

The old man who does not lose shape

With its appearance, the second generation caused a lot of noise in computer circles, which provided it with considerable popularity and excellent sales. DDR2, like its previous generation, could transmit data on both slices, but a faster bus with the ability to transfer data significantly increased its performance. In addition, a higher energy efficiency was a positive factor - at 1.8 V. And while this hardly affected the overall picture of the computer’s power consumption, it affected the service life (especially with intensive work of iron) purely.

However, technology has ceased to be such if it were not developed in the future. This is exactly what happened with the advent of the next generation of DDR3 in 2007, the task of which was to gradually but surely displace the aging DDR2 from the market. However, does this “obsolescence” really mean complete lack of competitiveness with new technology?

One on one with the third generation

In addition to traditional backward incompatibility, DDR3 introduced several technical innovations in RAM standards:

• The maximum supported capacity for serial motherboards increased from 16 to 32 GB (while the indicator of one module could reach 16 GB instead of the previous 8).
• Higher data transfer frequencies with a minimum of 2133 MHz and a maximum of 2800 MHz.
• Finally, the reduced power consumption standard for each new generation is 1.5 V versus 1.8 V in the second generation. In addition, two more modifications were developed based on DDR3: DDR3L and LPDDR3, consuming 1.35 V and 1.2 V, respectively.

Along with the new architecture, timings also increased, however, a drop in performance from this is offset by higher operating frequencies.

As the buyer decides

The buyer is not a development engineer; in addition to the technical characteristics, the price of the product itself will be equally important to the buyer.

At the start of sales of a new generation of any computer hardware, its cost will by default turn out to be higher. The same memory of a new type first comes to the market with a very large price difference compared to the previous one.

However, the increase in intergenerational performance in most applications, if not absent at all, is simply ridiculous, clearly not worthy of large overpayments. The only right moment to switch to a new generation of RAM is the maximum drop in its price tag to the level of the previous one (this always happens in the SDRAM sales segment, the same happened with DDR2 and DDR3, the same thing happened with DDR3 and the brand new DDR4). And only when the price of the overpayment between the last and previous generation will be the minimum (which is adequate for a small increase in productivity), then only in this situation can you think about replacing the RAM.

In turn, the owners of computers with DDR2 memory to acquire a new type of RAM is most rational only with a thorough upgrade with the appropriate replacement of the processor that supports this very new type, and a new motherboard (and even today it makes sense to upgrade to the level of components that support DDR4 -memory: its current price is on a par with DDR3, and the increase between the fourth and second generation will be much more noticeable than between the third and second).

Otherwise, if such an upgrade by the user is not planned at all, then it is quite possible to get by with the same DDR2, the price of which is now relatively low. It will be enough to only increase, if necessary, the total amount of RAM by similar modules. Permissible memory limits of this type even today more than cover all the needs of most users (in most cases, installing the additional DDR2 2Gb module will be enough), and the performance lag with the next generations is completely uncritical.

The minimum prices for RAM modules (only samples of trusted brands Hynix, Kingston and Samsung are taken into account) may vary depending on the region where the buyer lives and the store he chooses.