What is DDR2 and DDR3 and what is the difference between them. DDR2 vs DDR3, is there a big difference in performance? The difference between ddr and ddr2 memory

One of the most interesting technical features AMD Phenom II AM3 processors lies in the universal memory controller. This controller is designed to work with both DDR2 memory on AM2+ systems and DDR3 memory on AM3 systems. Naturally, the question immediately arises - which system is faster? We will try to answer it in the framework of this review.

For a perfect comparison of the performance of the memory subsystem, a single test platform is needed, on which only the memory modules themselves will change. It is very easy to ensure the identity of the test processor, power supply and video card. The search for a motherboard with simultaneous support for DDR2 and DDR3 memory turned out to be much more difficult. Ultimately, it was unsuccessful and we settled on two motherboards from the same manufacturer. These are the M4A79 Deluxe and M4A79T Deluxe models manufactured by ASUS. Both are based on the same chipset (AMD 790FX), both have an almost identical PCB design, with the only significant difference being support for different memory standards. This is exactly what we need.

Now - a few words about test modules. We used three kits: modules defended the honor of DDR2, and DDR3-1066 Qimonda and DDR3-1600 A-Data AD31600X001GU kits were their rivals.

It is worth emphasizing that the name of the modules and their nominal clock frequency are often weakly related to reality. For example - when installing Corsair modules, any motherboard AM2+ did not set the maximum mode of DDR2-1066 as standard, but quite moderate DDR2-800. For testing motherboards, these are simply ideal conditions, but today we are faced with the task of identifying the most fast system, which involves setting the memory frequency manually.

By the way, some readers may ask why the motherboard does not set the highest frequency. Here you need to take into account several interesting points. First, more low frequency expands the range of compatible memory modules, which ultimately increases the sales of this board. However, this doesn't always work. In particular, the M4A79 Deluxe board refused to start when very good G.Skill F2-6400CL4D-2GBHK modules were installed. And secondly, a higher memory frequency does not guarantee more high level performance. The fact is that along with an increase in frequency, working timings (or delays) increase. This leads to speed gains in some applications, but also slowdowns in others. Moreover, the performance of some applications does not depend on the memory latency and its bandwidth at all. Let's take an example. When installing Corsair modules, the M4A79 Deluxe board sets the following timings: 5-5-5-18-22-2T. When increasing the memory frequency to DDR2-1066, the timings increase to 5-7-7-24-30-2T. These modules are capable of working at tighter timings, but ASUS is reinsured. A similar picture is observed on the AM3 platform. At the stock DDR3-1066 frequency, the working timings of Qimonda modules are 7-7-7-20-27-1T, and after increasing the frequency to DDR3-1333, the board sets the timings to 9-9-9-25-34-1T. As a rule, timings are written in SPD and may differ for different modules. So, when setting the DDR3-1333 frequency on the A-Data modules, the board sets the timings to 9-9-9-24-33-1T (almost like on Qimonda), but when the frequency is lowered to DDR3-1066, the timings are reduced to only 8-8 -8-20-27-1T (for Qimonda, respectively, 7-7-7-20-27-1T).

Now let's move on to testing. Initially, we only wanted to compare three configurations: DDR2-800, DDR3-1066, and DDR3-1333. The choice is explained by the fact that these frequencies are standard for the AMD platform, and the results of the comparison will be of interest to the vast majority of users. However, to delve deeper into the issue, we added some more configurations. Firstly, this is the frequency of DDR2-1066. It is standard, but with a small feature: at this frequency, only two memory modules can work in the system (one module per channel). Here we note that the modules random access memory DDR2 has been around for a long time, technological process already well optimized, and the modules High Quality(i.e. overclockers) are quite cheap. This is a big plus for a system with an AM2+ processor.

By the way, at present the price difference for regular DDR2 and DDR3 modules is practically insignificant. But if we compare the cost of overclocker modules, then the situation is not so happy for fans of DDR3. In addition, impressive statistics have already been collected on overclocker DDR2 modules, which cannot be said about similar DDR3 modules. Thus, we believe that finding DDR2 modules capable of operating at DDR2-1066 with optimized timings is not a problem, just as it is not a problem to find modules operating at DDR2-800 with minimal timings. And it turned out that Corsair memory modules fit these requirements perfectly. Note that we are already talking about memory overclocking, i.e. on the operation of modules in modes not provided by manufacturers. Accordingly, you need to overclock the DDR3 memory. And here we were a little disappointed - Qimonda modules were unable to master the DDR3-1600 frequency, so we had to use A-Data modules. Moreover, when setting the DDR3-1600 frequency, the M4A79T Deluxe motherboard overestimated the timings so much that the first tests showed a significant drop in performance relative to DDR3-1333. So we had to increase Vmem to 1.88V (stock = 1.5V) and manually tighten the timings.

The following equipment was used in the test system:

Test equipment
CPU	Processor AMD Phenom II X3 720 (2.8 GHz; Deneb core)
cooler	Gigabyte 3D Cooler GP Edition
video card	ASUS 8800 GT (GeForce 8800 GT; PCI Express x16) Driver Version: 180.48WHQL
Sound card	-
HDD	Samsung HD160JJ
Memory	2x 1024 MB Corsair DDR2 TWIN2X2048-8500C5 2x 1024 MB Qimonda DDR3-1333 2x 1024MB DDR3-1600 A-Data AD31600X001GU
power unit	FSP 550W
OS	MS Vista

First, let's look at the results of synthetic tests.

Application software tests.

Data compression (WinRAR) was measured in kb/s, i.e. more is better.

Video encoding (DivX, Xvid) was measured in seconds, i.e. less is better.

Now - tests of game programs.

conclusions

If you look at the performance graphs from afar, then there is no difference between the performance of memory modules of different frequencies and different standards. Upon closer examination, several significant points can be noted. First, DDR3 is the preferred memory type for regular users. Moreover, the optimal ratio of frequency and timings is achieved in the modes provided by the manufacturer (ie DDR3-1066 for Qimonda and DDR3-1333 for A-Data). Secondly, increasing the frequency from DDR3-1066 to DDR3-1333 is accompanied by an increase in timings and increased delays "steal" a potential performance boost, so the system ends up running at the same speed. Thirdly, if the user is at least slightly familiar with memory settings, then he can configure a system with DDR2 in such a way that it will be as fast as a system with DDR3-1066. This result can be achieved in two ways: by seriously lowering the timings at DDR2-800, or by increasing the frequency to DDR2-1066 at medium timings. In these two cases, the RAM operates in normal modes, does not require an increase in the Vmem voltage, but forces the user to manually set the working timings. And finally, a conclusion for computer enthusiasts and overclockers - highest performance on the AMD Socket AM3 platform is achieved using DDR3-1600 memory with low timings. Accordingly, we are talking about rather expensive overclocker memory modules, which often require good compatibility with motherboard and a fairly significant increase in supply voltage (Vmem). In addition, the DDR3-1600 mode is non-standard (i.e. overclocker), and some motherboards may either not support it, or this mode is implemented "for show". Moreover, the potential of this mode (i.e. the HTT frequency and the corresponding memory multiplier) is revealed in two cases. Firstly, this is work in professional multi-threaded applications that require a large memory bandwidth, and in a multi-core system (currently AMD has a maximum of four cores). Secondly, overclockers who increase the HTT frequency to the range of 250-266 MHz and use high-quality modules with DDR3-2000 or DDR3-2133 operating frequencies can benefit from the DDR3-1600 mode.

DDR2 memory has some design differences from DDR modules, in particular, the number of pins has been increased from 184 to 240 (the pins are located closer to each other), and the “key” that prevents the power installation in a memory module slot of a different type has shifted.

The supply voltage in DDR2 is 1.8 V, in contrast to DDR modules - 2.5 V, as a result of which the memory has lower power consumption and heat dissipation, respectively.

The main architectural difference of DDR2 memory is the ability to transfer four data blocks per clock instead of two, as was the case with DDR.

DDR2 is based on the well-established Double Data Rate technology.
It provides for signal transmission on both fronts of the clock pulse (increasing and falling).
As a result, the actual clock speeds of 200 MHz and 266 MHz match the effective clock speeds of DDR2-400 and DDR2-533.

Among the new technical features of DDR2 are new system signal termination directly on the memory chips (ODT, On Die Termination), reduced page size (requires less power to activate) and fixed burst lengths of four or eight cycles.

In the latter case, the DDR2 specification implies a new burst mode called Sequential Nibble, in which each byte is divided into two 4-bit nibbles.
As a result, interleaved bursts of eight clocks are possible because each new column of the memory matrix can be used in conjunction with a new 4-bit prefetch.

The illustrations show delays during the reading process.
However, write latencies have also changed: while conventional DDR memory can write data immediately one cycle after a write command, this is not possible in the case of DDR2 due to higher clock frequencies.
Therefore, the write latency is calculated from the read latency by subtracting one cycle.

This is especially true for asynchronous operation (a typical case is when DDR2-533 memory is used on a platform with a frequency system bus 800 MHz) in single channel mode.
In this situation, the 33% increase in theoretical bandwidth of DDR2-533 compared to DDR400 often does not provide a noticeable performance boost.

In general, such inconsistencies could be ignored, especially since in the case of using the synchronous mode (system bus 1066 MHz), the use of this type of memory rehabilitates itself.

Using Posted CAS allows you to issue a CAS command directly after the RAS signal without any collisions.
This simplifies the design of the controller, and increases the speed of working with memory.

Further differences between DDR and DDR2 concern details: instead of TSO (Thin Small Outline) packaging, only FBGA (Fine-Line Ball Grid Array) packaging is allowed.
In addition to reducing circuits and reducing signal noise, the FBGA is more compact, allowing high-density memory to be built.

From DDR2-533 in dual-channel mode, we get a speed of 8.533 MB / s (8.33 GB / s) - sounds good.
However, there are two important factors that reduce the additional performance potential.

Firstly, call delays have increased to CL 4 and 4-4-12, and they may increase further.

Secondly, the frequency of 533 MHz (DDR) means asynchronous operation with the 800 MHz FSB of the P4 processor (QDR) in a ratio of 2:3 - in the past this was often not always justified.

Memory vendors have been successful in promoting their latest high-end products: DDR3-2000 speeds are currently considered state-of-the-art for Intel platforms based Intel chipsets P35, X38, X48 for enthusiasts or the new nVidia 7 line. But does it make sense to buy such memory? While mainstream DDR2 memory has reached a ridiculously low price point (you can buy two 2GB DDR2-800 modules for $90-100), DDR3 memory at 1600 and above costs five times as much, and the performance gain is negligible. In fact, for the vast majority of users, the difference between mass and high-end memory is very small.

The value of RAM (Random Access Memory, RAM) has changed a lot over time. At the beginning of the millennium, there was a significant difference in performance between CL2 and CL3 latencies, when the first generation SDRAM memory type with PC100 and PC133 speeds was popular. But now, when using high-speed DDR2 or DDR3 SDRAM memory modules, the difference in performance between low and high timings is almost negligible. Although memory latencies increase from generation to generation (CL2/3 with DDR1, CL3-5 with DDR2, CL5 and up with DDR3), they haven't changed much as clock speeds double with each generation, potentially offsetting latency increases. Thus, effective delays practically do not change, but the throughput has increased significantly.

Enthusiast memory has another point that is only tangentially related to performance: overclockers look to components for the ultimate in flexibility when they want to squeeze the most performance out of their systems. Increasing the system bus clock speed is often the only way increase the clock frequency of the central processor, which automatically overclocks the memory, since the frequency of the memory bus directly depends on FSB frequencies. Since you do not want to lose performance due to limited memory speed, you may need high-speed memory to achieve maximum system performance. However, this scenario is only valid for hardcore overclockers, since the advantage of fast memory over slow memory is very small, if other components and parameters remain the same.

We want to find out how important memory speed and latency really are. For testing, we built a Socket 775-based system that we ran with two different processors: a new 3.16GHz Core 2 Duo E8500 processor on a 45nm Core 2 Duo Wolfdale core with 6MB of L2 cache and a single-core 3.73- GHz Pentium 4 processor Extreme Edition. We decided to use the old Netburst P4 single-core P4 processor because it has a smaller and less efficient cache than the Core 2 Duo. Both processors were tested at DDR2-667, DDR2-800, and DDR2-1066, as well as DDR3-1066 and DDR3-1333, using low and high latencies each time. However, P4 could not be tested on DDR3-1333, as this would require the FSB1333 bus.

Memory selection

The memory market is in the process of transitioning from DDR2 to the more power efficient and denser DDR3 memory; this process will continue until the end of 2008. DDR2 is available at speeds of 800 and 1066, while DDR3 has so far increased the speed from 800 to 1333 MHz (effective frequency indicated). Faster products are still aimed at enthusiasts as platforms don't officially support 1600+ speeds yet.

Both DDR2 and DDR3 are based on the principle of doubling data transfer per clock, i.e. data is transmitted on the rise and fall of the clock pulse. Each new generation of DDR features smaller transistors, lower voltages, and higher memory densities. While the internal clock has not changed, the interface (I/O buffer) clock has increased due to the increased prefetch size. DDR3-1600 memory runs at a physical clock speed of 200 MHz, but with a prefetch size of 8 bits. The interface clock is 800 MHz, but thanks to the technology of double data transfer, this is equivalent to a frequency of 1600 MHz. The base clock speed of DDR2-800 memory is also 200 MHz, but the prefetch size is 4 bits.

As mentioned earlier, performance is not a sufficient reason to move from one generation of memory to another. Of greater interest is the memory density. So far, 1GB memory modules (1GB chips) can be considered mainstream in the DDR2 memory market, but DDR3 memory will soon begin to dominate when 2GB DDR3 modules become affordable, and AMD will also switch to this memory (toward the end of the year ).

What is the best memory to buy?

Be that as it may, the most profitable proposition can be found on the mainstream DDR2 module market. If it's all about money, any 2x 1GB DDR2 kit at DDR2-800 speeds is worth a look. As the test results will show, only memory with a significantly higher speed (and significantly more high price) can provide a small performance boost. We don't even recommend chasing DDR3 capable motherboards unless you're buying a high-end product. When you buy a motherboard for a few hundred dollars and a Core 2 Quad processor in the same price range, plus other decent system components, it's perfectly acceptable to spend more on memory. But for users with a limited budget, this is unacceptable.

2GB memory kits with two DDR2-800 modules start at about $40. This can be considered a bargain, given that 2 GB of main memory is enough to run all the main applications and games. More memory, ie. 4 GB, requires a 64-bit operating system because 32-bit Windows versions XP and Windows Vista can only use 3 GB of RAM. While 64-bit versions are also readily available, almost as fast, and driver support has improved a lot, we strongly recommend that you make sure that your devices and applications will run in a 64-bit environment.

DDR2 specification
Standard name	Memory frequency	Takt time	Bus frequency		Module name
DDR2-400	100 MHz	10 ns	200 MHz	400 million	PC2-3200	3,200 MB/s
DDR2-533	133 MHz	7.5 ns	266 MHz	533 million	PC2-4200	4,266 MB/s
DDR2-667	166 MHz	6 ns	333 MHz	667 million	PC2-5300	5333 MB/s
DDR2-800	200 MHz	5 ns	400 MHz	800 million	PC2-6400	6400 MB/s
DDR2-1066	266 MHz	3.75 ns	533 MHz	1,066 million	PC2-8500	8,533 MB/s

On this moment we recommend ordinary users pay attention to DDR2-800 memory. Fast timings (low CL delays) are preferred, but don't shell out much more money for them as the difference is small. DDR2-1066 memory is important for systems based on AMD processors Phenom because their memory controllers can handle faster memory.

DDR3 specification
Standard name	Memory frequency	Takt time	Bus frequency	Number of data transfers per second	Module name	Peak Data Rate
DDR3-800	100 MHz	10 ns	400 MHz	800 million	PC3-6400	6400 MB/s
DDR3-1066	133 MHz	7.5 ns	533 MHz	1,066 million	PC3-8500	8,533 MB/s
DDR3-1333	166 MHz	6 ns	667 MHz	1,333 million	PC3-10600	10,667 MB/s
DDR3-1600	200 MHz	5 ns	800 MHz	1,600 million	PC3-12800	12,800 MB/s

As far as DDR3 memory is concerned, we recommend holding off on buying it, as high-speed models are still much more expensive than DDR2 memory and don't offer much better performance. Even with regard to high-capacity memory kits, we can say the following: sets of four 2GB DDR2 modules are much cheaper than equivalent DDR3 memory.

RAM is a special microcircuit used to store all sorts of data. There are many varieties of these devices, they are produced by various companies. The best manufacturers are most often of Japanese origin.

What is it and why is it needed?

RAM (so-called RAM memory) is a type of volatile microcircuit used to store all sorts of information. Most often it contains:

• machine code of currently executing programs (or those in standby mode);
• input and output data.

Data exchange between the CPU and RAM is carried out in two ways:

• using an ultra-fast register ALU;
• through a special cache (if available in the design);
• directly (directly via the data bus).

The devices under consideration are circuits built on semiconductors. All information stored in various electronic components remains accessible only in the presence of electric current. As soon as the voltage is turned off completely, or a short-term power failure occurs, then everything that was contained inside the RAM is erased or destroyed. The alternative is ROM type devices.

Types and amount of memory

The board today can have a volume of several tens of gigabytes. Modern technical means allow you to use it as quickly as possible. Most operating systems are equipped with the ability to interact with such devices. There is a proportional relationship between the amount of RAM and the cost. The larger it is, the more expensive it is. And vice versa.

Also, the devices in question may have a different frequency. This parameter determines how fast the interaction between the RAM and other PC devices (CPU, data bus and video card) is carried out. The higher the speed of work, the more operations the PC will perform per unit of time.

The value of this characteristic also directly affects the cost of the device in question. The modern fastest modification can "remember" 128 GB. It is produced by a company called Hynix and has the following performance characteristics:

Then the working memory appearance could have been completely unpredictable. More often these were magnetic drums or shafts.

With the release of the second generation of computers, it was necessary to think about effective RAM. Just then, magnetic cores with memory appeared. The third generation made a leap forward and began to use microcircuits on which there were electronic components of a computer. Then types of random access memory already began to appear. Dynamic was preserved due to the charge of the capacitor, and static - with the help of flip-flops.

The current state of affairs

In the meantime, Nvidia, in order not to force gamers to wait for the release of a Game Ready driver optimized specifically for the new shooter from MachineGames, has released a small "patch" in the form of GeForce 388.10 Hotfix.
The key task of the new release was to ensure the stable operation of Wolfenstein: The New Colossus on video cards of the Kepler generation.
The release of a full-fledged Game Ready driver is scheduled for next week.

New malware to steal money from ATMs

Kaspersky Lab has discovered a new malware that allows attackers to steal money from ATMs.

The malware is reportedly named Cutlet Maker.
To attack an ATM, a criminal needs to gain access to its USB port.
After that, you need to consistently use a number of software tools.

Cutlet Maker includes a special Stimulator module that displays the number and denomination of banknotes in ATM cassettes.
This allows the attacker to initially select the cell containing the largest amount of money, and not to act "blindly", sorting through the cassettes one by one.
Thus, the time to carry out the attack is reduced, and consequently, the chances of catching criminals at the scene of the robbery are reduced.

The situation is further aggravated by the fact that the Cutlet Maker malware is offered to anyone on the underground Internet market.
The malware costs $5,000, and the kit includes step-by-step instructions.
Thus, even the most inexperienced attacker can commit a crime.

It is not yet clear who exactly is behind the development of Cutlet Maker.
But analysis shows that English is not their native language for the creators of the malware.

Apple may block smartphones with a non-original display

With the release of iOS 11.0.3, Apple has the ability to block smartphones and tablets with a non-original display installed.

Therefore, now the "apple" manufacturer can remotely control devices and track which components are used in them.

Apple commented on the update:

“Resolved an issue with touch input not working on the iPhone 6S, which caused the screens of some devices to become unresponsive to touch due to counterfeit components.
Replacing defective displays with non-original displays may result in poor image quality and performance problems.
Apple-certified repairs are performed by experts using genuine parts."

Previously, the owners of the iPhone 6S received complaints about the marriage of the display.
Some users have repaired their gadgets not in certified service centers.
At some point, their touch input stopped working.
Apple then released an update, remotely fixing the issue.
Also, the manufacturer strongly recommended that the iPhone be repaired only in authorized service centers.

Thus, at some point, millions of iPhones, iPads and other Apple products can stop working if they were repaired by third-party specialists.

Antivirus added to Chrome for Windows

Google has released a new version of the Chrome desktop browser for Windows.
The update brings built-in anti-malware capabilities.

So, now Chrome determines whether the browser settings have been changed without the user's knowledge and offers to return the settings to their previous form in case of a change.

Also, a kind of built-in antivirus appeared in the browser.
It will offer to remove any suspicious or malware from a PC, including with an inconspicuous installation.
The ESET engine is used to detect malware.

Updated: 15.08.2019 11:02:21

Judge: Savva Goldshmid

At one time, DDR RAM became a real breakthrough not only in a professional environment - users appreciated not only a fashionable, but also an incredibly productive device. And the appearance of the second and third generations made it possible to talk about super speeds. So, what exactly is DDR2 and DDR3, how do you tell them apart, and which version is better? Our experts figured out the answer.

All the predecessors of the DDR that became the reference, used until 1995, at one time seemed to be those "tough guys". But when DIMM or the so-called SDRam appeared, in the world of computer technology, it gradually began to gain ground new era- the era of high-speed devices. SDRam lasted until 2001 and was built into almost all sold by Intel and Celeron.

This type of RAM was replaced by DDRs that created a real stir. Unlike the previous generation RAMs, their work was accelerated not by doubling the clock frequency, but by transferring data twice in one cycle.

But our topic today is not the first Double Data Rate, but the second and third generations of this RAM. Speaking of DDR2, one cannot fail to note the presence of a much faster bus in it, as well as the ability to transfer data on both slices, and simultaneously from four places. In addition, compared to the first generation RAM, DDR2 has less “appetite”, consuming little power, and at the same time cools very quickly.

Main features of DDR2:

The maximum data transfer frequency is 800 MHz (in rare cases, there are models overclocked to 1066 MHz). By the way, the higher this indicator, the faster the information will be processed, therefore, there will be more productivity;

Timing (allows you to determine the delay time of the RAM) - for a model with a maximum clock frequency(533 MHz) this indicator is 4-4-4-12.

Power consumption (1 bar) - about 1.8 V;

The maximum possible amount of memory is 16 GB (serial motherboards), less often - 32 GB (mainly server boards).

At one time, the second-generation RAM was considered the most effective of the existing options. But technology does not stand still: it was replaced by DDR3, the developers of which did their best, reducing power consumption by an incredible 15%. In the computer component market, you can find a modified version of DDR3 marked "L", indicating an even lower level of power consumption.

Main features of DDR3:

The maximum data transfer frequency is 2400 MHz (there are already models on the market overclocked to 3000 MHz);

Timing - for a model with a maximum clock frequency (1200 MHz), this figure is 10-10-10-30.

Power consumption (1 bar) - 1.5 V, in DDR3L varieties - 1.35 V;

The maximum possible amount of memory is not limited (the starting mark is 64 GB). Is it true that such figures are in demand? But that's another question.

Again, a modest "appetite" is not the most important thing in DDR3: of course, it's all about efficiency. However, the third generation is no longer the market leader. It was replaced by a new model of RAM type Double Data Rate - DDR4. But today is not about her.

The main differences between these two types of RAM are as follows:

Clock frequency- DDR3 RAM boasts a higher rate of 1200 MHz, which is 2 times higher than the second generation RAM (533 MHz).

Bandwidth- for third-generation RAM (DDR3), it is much higher than for the second (DDR2), while the level of energy consumed is very low (it increases slightly when overclocking the processor).

Physical Configuration- a clear external difference between the types of RAMs under consideration (different slots) also affected compatibility - it is simply absent. In view of last feature two devices, we do not recommend installing DDR2 and DDR3 on the same motherboard.

ON A NOTE. Today, manufacturers offer users to purchase so-called hybrids, the peculiarity of which, as you might guess from the name, is the combination of two types of RAM on one device. Such products have connectors immediately for 2 types of RAM. But it must be taken into account that they can only be used separately.

Which option to choose for yourself? It all depends on the characteristics of the computer device, the requirements for the speed of RAM, as well as the tasks that will be performed. For most users, DDR2 is a great solution, which is fully justified. For those who have increased requests for such details, it is better to pay attention to DDR3.