The new DDR4 RAM standard will improve performance. Practical comparison of DDR3 and DDR4 memory on the Intel LGA1151 platform in terms of performance and power consumption. What is the operating frequency of ddr4 RAM?

Here come the processors Intel Haswell-E. The site has already tested the top 8-core Core i7-5960X, as well as the ASUS X99-DELUXE motherboard. And, perhaps, the main feature of the new platform is support for the DDR4 RAM standard.

The beginning of a new era, the DDR4 era

About the SDRAM standard and memory modules

The first SDRAM modules appeared back in 1993. They were released by Samsung. And by 2000, SDRAM memory, due to the production capacity of the Korean giant, had completely ousted the DRAM standard from the market.

The abbreviation SDRAM stands for Synchronous Dynamic Random Access Memory. This can be literally translated as “synchronous dynamic random access memory”. Let us explain the meaning of each characteristic. Memory is dynamic because, due to the small capacity of the capacitors, it constantly requires updating. By the way, in addition to dynamic memory, there is also static memory, which does not require constant data updating (SRAM). SRAM, for example, underlies cache memory. In addition to being dynamic, the memory is also synchronous, unlike asynchronous DRAM. Synchronicity means that the memory performs each operation for a known amount of time (or clock cycles). For example, when requesting any data, the memory controller knows exactly how long it will take for it to get to it. The synchronicity property allows you to control the flow of data and queue it. Well, a few words about “random access memory” (RAM). This means that you can simultaneously access any cell at its address for reading or writing, and always at the same time, regardless of location.

SDRAM memory module

If we talk directly about the design of memory, then its cells are capacitors. If there is a charge in the capacitor, then the processor regards it as a logical unit. If there is no charge - as a logical zero. Such memory cells have a flat structure, and the address of each of them is defined as the row and column number of the table.

Each chip contains several independent memory arrays, which are tables. They are called banks. You can work with only one cell in a bank per unit of time, but it is possible to work with several banks at once. The information being recorded does not have to be stored in a single array. Often it is split into several parts and written to different banks, and the processor continues to consider this data as a single whole. This recording method is called interleaving. In theory, the more such banks in memory, the better. In practice, modules with a density of up to 64 Mbit have two banks. With a density of 64 Mbit to 1 Gbit - four, and with a density of 1 Gbit and higher - already eight.

What is a memory bank

And a few words about the structure of the memory module. The memory module itself is a printed circuit board with chips soldered on it. As a rule, you can find devices on sale made in the DIMM (Dual In-line Memory Module) or SO-DIMM (Small Outline Dual In-line Memory Module) form factors. The first is intended for use in full-fledged desktop computers, and the second - for installation in laptops. Despite the same form factor, memory modules of different generations differ in the number of contacts. For example, an SDRAM solution has 144 pins to connect to motherboard, DDR - 184, DDR2 - 214 pins, DDR3 - 240, and DDR4 - already 288 pieces. Of course, in this case we are talking about DIMM modules. Devices made in the SO-DIMM form factor naturally have a smaller number of contacts due to their smaller sizes. For example, a DDR4 SO-DIMM memory module is connected to the motherboard using 256 pins.

The DDR module (bottom) has more pins than SDRAM (top)

It is also quite obvious that the volume of each memory module is calculated as the sum of the capacities of each soldered chip. Memory chips, of course, can differ in their density (or, more simply, in volume). For example, last spring Samsung launched mass production of chips with a density of 4 Gbit. Moreover, in the foreseeable future it is planned to release memory with a density of 8 Gbit. Memory modules also have their own bus. The minimum bus width is 64 bits. This means that 8 bytes of information are transmitted per clock cycle. It should be noted that there are also 72-bit memory modules in which the “extra” 8 bits are reserved for ECC (Error Checking & Correction) error correction technology. By the way, the bus width of a memory module is also the sum of the bus widths of each individual memory chip. That is, if the memory module bus is 64-bit and there are eight chips soldered on the strip, then the memory bus width of each chip is 64/8 = 8 bits.

To calculate the theoretical bandwidth of a memory module, you can use the following formula: A*64/8=PS, where “A” is the data transfer rate, and “PS” is the desired throughput. As an example, we can take a DDR3 memory module with a frequency of 2400 MHz. In this case, the throughput will be 2400*64/8=19200 MB/s. This is the number referred to in the marking of the PC3-19200 module.

How does information directly read from memory occur? First, the address signal is sent to the corresponding row (Row), and only then the information is read from the desired column (Column). The information is read into the so-called Sense Amplifiers - a mechanism for recharging capacitors. In most cases, the memory controller reads an entire packet of data (Burst) from each bit of the bus at once. Accordingly, when recording, every 64 bits (8 bytes) are divided into several parts. By the way, there is such a thing as data packet length (Burst Length). If this length is 8, then 8*64=512 bits are transmitted at once.

Memory modules and chips also have such a characteristic as geometry, or organization (Memory Organization). The module geometry shows its width and depth. For example, a chip with a density of 512 Mbit and a bit depth (width) of 4 has a chip depth of 512/4 = 128M. In turn, 128M=32M*4 banks. 32M is a matrix containing 16000 rows and 2000 columns. It can store 32 Mbit of data. As for the memory module itself, its capacity is almost always 64 bits. The depth is easily calculated using the following formula: the volume of the module is multiplied by 8 to convert from bytes to bits, and then divided by the bit depth.

You can easily find the timing values ​​on the markings

It is necessary to say a few words about such characteristics of memory modules as timings. At the very beginning of the article, we said that the SDRAM standard provides for such a point that the memory controller always knows how long a particular operation takes to complete. Timings precisely indicate the time required to execute a certain command. This time is measured in memory bus clocks. The shorter this time, the better. The most important delays are:

• TRCD (RAS to CAS Delay) - the time required to activate the bank line. Minimum time between activation command and read/write command;
• CL (CAS Latency) - time between issuing a read command and the start of data transfer;
• TRAS (Active to Precharge) - line activity time. Minimum time between activating a line and the command to close the line;
• TRP (Row Precharge) - time required to close a row;
• TRC (Row Cycle time, Activate to Activate/Refresh time) - time between activation of rows of the same bank;
• TRPD (Active bank A to Active bank B) - time between activation commands for different banks;
• TWR (Write Recovery time) - time between the end of writing and the command to close the bank line;
• TWTR (Internal Write to Read Command Delay) - time between the end of the write and the read command.

Of course, these are not all the delays that exist in memory modules. You can list a dozen more different timings, but only the above parameters significantly affect memory performance. By the way, only four delays are indicated in the labeling of memory modules. For example, with parameters 11-13-13-31, the CL timing is 11, TRCD and TRP are 13, and TRAS is 31 clock cycles.

Over time, the potential of SDRAM reached its ceiling, and manufacturers were faced with the problem of increasing the speed of RAM. This is how the DDR.1 standard was born

The Coming of DDR

The development of the DDR (Double Data Rate) standard began back in 1996 and ended with the official presentation in June 2000. With the advent of DDR, SDRAM memory became a thing of the past and was simply called SDR. How does the DDR standard differ from SDR?

After all SDR resources were exhausted, memory manufacturers had several options to solve the problem of improving performance. It would be possible to simply increase the number of memory chips, thereby increasing the capacity of the entire module. However, this would have a negative impact on the cost of such solutions - this idea was very expensive. Therefore, the JEDEC manufacturers association took a different route. It was decided to double the bus inside the chip, and also double the data transfer increased frequency. In addition, DDR provided for the transmission of information on both edges of the clock signal, that is, twice per clock. This is where the abbreviation DDR - Double Data Rate - comes from.

Kingston DDR Memory Module

With the advent of the DDR standard, such concepts as real and effective memory frequency appeared. For example, many DDR memory modules ran at 200 MHz. This frequency is called real. But due to the fact that data transfer was carried out on both edges of the clock signal, manufacturers, for marketing purposes, multiplied this figure by 2 and obtained a supposedly effective frequency of 400 MHz, which was indicated in the labeling (in this case, DDR-400). At the same time, the JEDEC specifications indicate that using the term “megahertz” to characterize the level of memory performance is completely incorrect! Instead, "millions of transfers per second per data output" should be used. However, marketing is a serious matter, and few people were interested in the recommendations specified in the JEDEC standard. Therefore, the new term never took root.

Also in the DDR standard, a dual-channel memory mode appeared for the first time. It could be used if there was an even number of memory modules in the system. Its essence is to create a virtual 128-bit bus by interleaving modules. In this case, 256 bits were sampled at once. On paper, a dual-channel mode can double the performance of the memory subsystem, but in practice the speed increase is minimal and is not always noticeable. It depends not only on the RAM model, but also on timings, chipset, memory controller and frequency.

Four memory modules operate in dual-channel mode

Another innovation in DDR was the presence of a QDS signal. It is located on printed circuit board along with data lines. QDS was useful when using two or more memory modules. In this case, the data arrives at the memory controller with a slight time difference due to different distances before them. This creates problems when choosing a clock signal for reading data, which QDS successfully solves.

As mentioned above, DDR memory modules were made in DIMM and SO-DIMM form factors. In the case of DIMMs, the number of pins was 184 pieces. In order for DDR and SDRAM modules to be physically incompatible, the key for DDR solutions (the cut in the pad area) was located in a different location. In addition, DDR memory modules operated at a voltage of 2.5 V, while SDRAM devices used a voltage of 3.3 V. Accordingly, DDR had lower power consumption and heat dissipation compared to its predecessor. The maximum frequency of DDR modules was 350 MHz (DDR-700), although JEDEC specifications only provided for a frequency of 200 MHz (DDR-400).

DDR2 and DDR3 memory

The first DDR2 modules went on sale in the second quarter of 2003. Compared to DDR, second-generation RAM has not received significant changes. DDR2 used the same 2n-prefetch architecture. If previously the internal data bus was twice as large as the external one, now it has become four times wider. At the same time, the increased performance of the chip began to be transmitted via an external bus at double the frequency. Precisely frequency, but not double transmission speed. As a result, we found that if the DDR-400 chip operated at a real frequency of 200 MHz, then in the case of DDR2-400 it operated at a speed of 100 MHz, but with twice the internal bus.

DDR2 modules also received large quantity contacts to connect to the motherboard, and the key was moved to another location for physical incompatibility with SDRAM and DDR sticks. The operating voltage has been reduced again. While DDR modules operated at a voltage of 2.5 V, DDR2 solutions operated at a potential difference of 1.8 V.

By and large, this is where all the differences between DDR2 and DDR end. At first, DDR2 modules were characterized by high latencies, which made them inferior in performance to DDR modules with the same frequency. However, the situation soon returned to normal: manufacturers reduced latencies and released faster sets of RAM. The maximum DDR2 frequency reached an effective 1300 MHz.

Different key positions for DDR, DDR2 and DDR3 modules

The transition from DDR2 to DDR3 followed the same approach as the transition from DDR to DDR2. Of course, data transmission at both ends of the clock signal has been preserved, and the theoretical throughput has doubled. DDR3 modules retained the 2n-prefetch architecture and received 8-bit prefetch (DDR2 had 4-bit). At the same time, the internal tire became eight times larger than the external one. Because of this, once again, with the change of memory generations, its timings increased. The nominal operating voltage for DDR3 has been reduced to 1.5 V, making the modules more energy efficient. Note that, in addition to DDR3, there is DDR3L memory (the letter L means Low), which operates with a voltage reduced to 1.35 V. It is also worth noting that DDR3 modules turned out to be neither physically nor electrically compatible with any of the previous generations of memory.

Of course, DDR3 chips have received support for some new technologies: for example, automatic signal calibration and dynamic signal termination. However, in general, all changes are predominantly quantitative.

DDR4 - another evolution

Finally, we get to the completely new DDR4 memory. The JEDEC Association began developing the standard back in 2005, but only in the spring of this year the first devices went on sale. As stated in a JEDEC press release, during development, engineers tried to achieve the highest performance and reliability, while increasing the energy efficiency of the new modules. Well, we hear this every time. Let's see what specific changes DDR4 memory has received in comparison with DDR3.

In this picture you can trace the evolution of DDR technology: how the voltage, frequency and capacitance indicators changed

One of the first DDR4 prototypes. Oddly enough, these are laptop modules

As an example, consider an 8GB DDR4 chip with a 4-bit wide data bus. Such a device contains 4 groups of banks, 4 banks each. Inside each bank there are 131,072 (2 17) rows with a capacity of 512 bytes each. For comparison, you can give the characteristics of a similar DDR3 solution. This chip contains 8 independent banks. Each bank contains 65,536 (2 16) rows, and each row contains 2048 bytes. As you can see, the length of each line of a DDR4 chip is four times less than the length of a DDR3 line. This means that DDR4 scans banks faster than DDR3. At the same time, switching between the banks themselves also occurs much faster. Let us immediately note that for each group of banks there is an independent choice of operations (activation, read, write or regeneration), which allows increasing the efficiency and memory bandwidth.

The main advantages of DDR4: low power consumption, high frequency, large capacity of memory modules

In order for modern games to run faster, the computer needs not only , but also a sufficient amount of RAM. Why is this necessary? Today's games have very large locations with a considerable number of objects, which are stored in the RAM. If there is not enough RAM, the game will access permanent memory and, if it is a slow HDD, the user will invariably receive freezes.

Corridor shooters may not require a lot of memory, but if you play large-scale RTS or FPS games, this makes a difference. For example, to play Battlefield 1, the manufacturer recommends using 16 GB of RAM or higher. If you have not yet decided how much RAM you need, use ours.

Samsung DDR4 2666 DIMM 8Gb

Probably, almost every user has heard about this sensational model from Samsung. Unfortunately, you won’t find a set of several planks, but nothing prevents you from buying one piece at a time and installing them together. In addition to the extremely low cost, given memory It has excellent overclocking potential, which is why overclockers love this RAM. The stock speed here is only 2666 MHz, but without much difficulty on a good motherboard this module will take the frequency from 3200 to 3666 MHz, despite the fact that dual-rank memory usually runs worse than single-rank memory.

Advantages

Excellent overclocking potential
Very cheap
Very common in the market

Flaws

Appearance - couldn’t be simpler

Patriot Memory PV416G320C6K

If you don’t want to overclock, but your budget is very limited, then we recommend looking towards the Patriot Memory company. The factory overclocked kit has a frequency of 3200 MHz. If you want, you can, of course, try to squeeze more, but most likely you won’t succeed. The dual-rank memory PV416G320C6K will run at 3200 MHz only when the XMP profile is activated and the timings are increased. Out of the box you will only see a measly 2133 MHz.

Besides high frequency, the developers offer the user an interesting design that will fit well into the red assembly. In addition, it is possible to detach the radiator if suddenly you cannot install a tower cooler to cool the processor. The kit comes with a 10-year warranty!

Advantages

Low cost
High frequency with XMP profile support
Nice design
Detachable radiators
10 years warranty

Flaws

No specific memory chip vendor

Kingston HyperX HX432C16PB3K2/16

Kingston is one of the oldest memory manufacturers on the market. Its HyperX brand is aimed at gamers, and its products meet high quality standards. It is not surprising that the memory kit HyperX HX432C16PB3K2/16 A lifetime guarantee is provided. Of course, this is not the cheapest option, but it still works out very well on a budget.

The operating memory frequency of this model is the same as the previous set - 3200 MHz with support for the XMP profile, but overclocking is much more stable. Apparently, this is precisely what the buyer overpays for when compared with Patriot Memory PV416G320C6K. It is also worth noting the traditional black aggressive style of Kingston.

Advantages

Lifetime Warranty
Stable overclocking
Interesting design

Flaws

Slightly overpriced

Patriot Memory PVS416G400C9K

If you own a processor from Ryzen, then you are probably looking at high-frequency memory that is overclocked from the factory. Patriot Viper brings to your attention the cheapest “whale” on the market, which will operate at 4000 MHz. Of course, in order to run the bars at such a frequency, you will need to dance with a tambourine for a long time in any case, but the performance gain is worth it. Please note that even the highest quality peer-to-peer models built on B-die chips will not always be able to reach the 400 MHz mark. So why pay more for a brand then, right?

Advantages

Interesting design
High frequency from factory
B-die chips are often found
Low cost
Almost always in stock

The standardizing organization JEDEC Solid State Technology Association has presented the official final version of the specification for the Synchronous DDR4 RAM standard ( Double Data Rate 4).

Its introduction is to ensure a new level of RAM performance, its reliability and reduction in energy consumption.

DDR4 memory includes a number of modern advances that will allow the new type of memory to become widespread in computer devices- from household appliances to servers and even more powerful computer systems.

• The performance level per slot in DDR4 is set at 1.6 billion transfers per second, with the possibility of reaching a maximum level of 3.2 billion/s in the future.
• The minimum operating frequency of DDR4 memory is 2133 MHz to 4266 MHz, which is 1000 MHz more than its predecessor (1333 MHz and 1666 MHz in the previous generation standard).
• For memory with a frequency of 2133 MHz (the lowest frequency for DDR4 memory), the maximum bandwidth will be 2133 * 8 = 17,064 Megabytes/s.
• For memory with a frequency of 4266 MHz (the highest frequency defined in the standard), the maximum bandwidth will be 4266 * 8 = 34,128 Megabytes/s.
• The operating voltage is reduced: 1.1 V - 1.2 V versus 1.5 V in DDR3.
• The proposed technical process is 32 and 36 nm.

The DDR4 architecture allows 8 bits of data per clock prefetch (8n prefetch) with two or four selectable groups of memory blocks. This allows devices to perform independent activation, reading, writing and updating operations through separate memory blocks.

All of the above features, as well as a number of smaller changes and innovations, have significantly increased memory efficiency DDR4.

DDR4 module has 284 contacts, while standard DDR3 modules only have 240 contacts.

IN SO-DIMM versions will be presented 256 contacts, and DDR3 SO-DIMMs have only 204 pins.

In the DDR4 specifications, for the first time, a description of working with memory in multi-chip packaging appeared. The standard allows a column (stack) of eight crystals. Moreover, all crystals are “hung” on common signal lines. This was done not because it is better this way (although it does simplify the steps to expand the memory space), but for the reasons that in general the ideology of DDR4 memory is to connect modules with controllers in a point-to-point manner.

There will be many channels, not two or four, so each of them needs to provide the highest possible performance without overloading the exchange mechanisms. In the same vein, we must consider the possibility of independent simultaneous operation of two or four memory banks. For each group of banks, all basic operations such as read, write and regeneration are architecturally allowed simultaneously.

According to iSuppli's forecast, by 2014 the level of penetration of the DDR4 memory market will be 12%, by 2015 - 56%. However, manufacturers may rush to implement the new standard, prompted by the desire to raise prices for their products, which are currently at an extremely low level. Micron, for example, announced back in May the development of the first full-featured module and plans to begin mass production at the end of this year. Samsung has already demonstrated the 284-pin PC4-17000 memory (2133 MHz). All that remains is to wait for their support from Intel and AMD. Intel plans to begin DDR4 support in early 2014 in high-end 4-socket server systems based on Haswell-EX processors, but ordinary users will probably have to wait until 2015, since neither the 22 nm Haswell processors nor the subsequent 14 nm Broadwell processors support DDR4 is not provided.

The DDR4 standard is just one of the first steps towards widespread adoption of next-generation memory. Applications for DDR4 memory include servers, laptops, desktop PCs and consumer electronics products. First, DDR4 will appear in server systems, and after that mass production of such memory for consumer computers will begin.

We checked what new DDR4 RAM modules differ from previously used DDR3 memory modules and how much more efficient they are previous generation equipment.

First DDR4 memory information appeared in 2008. It was then assumed that it would hit stores within five years and very quickly gain more popularity than DDR3 memory.

It soon became clear, however, that the memory used had very great potential for development, and Fast passage on new standard doesn't make sense. Therefore, although several years ago at various exhibitions computer companies showed their DDR4 memory models, due to the lack of supporting platforms there was no possibility of its practical use. Everything has changed over the past year. DDR3 memory has reached its limit.

The end of the era of DDR3 memory

Although modules with DDR-2400, DDR-2800, and even faster frequencies are available on the market, further acceleration turned out to be almost impossible. True, some manufacturers managed to obtain higher clock speeds, but creating such memory modules on a mass scale was unprofitable and practically impossible.

Constant acceleration existing type RAM is impractical - power consumption increases significantly and fault tolerance decreases. The solution to these problems turned out to be DDR4 memory modules, which have much more opportunities to increase performance, while consuming significantly less energy.

Do we need new DDR4 memory modules?

Yes, and not only because of the speed. The first memory models of the new type do not have greater performance than the previous generation modules.

When one technology reaches its limits and the other is just entering the market, we may not notice a difference in speed between them. In this case, it is not performance that is important, but prospects new technology. Therefore, now, when upgrading your computer, it is worth thinking about choosing a platform compatible with the new type of memory.

The next time we replace components, we will be able to use new generation modules. If after some time we realize that the memory used is too slow or insufficiently capacious, then we will not have problems purchasing more powerful components - otherwise the situation is in the case of DDR3 memory, which has reached its limit and will slowly leave the market.

One of strengths DDR4 memory is its energy efficiency. Currently, the vast majority of computers sold are laptops, tablets and convertible devices. The most important feature of such equipment is its performance and operating time without recharging, which, in turn, depends specifically on energy consumption.

Is it worth changing the memory to DDR4?

For now, such a dilemma does not exist because a platform that supports both types of memory is not yet available. Therefore, replacing memory will result in replacing the entire platform. However, expect motherboards that support both memory types to be available soon.

Is it worth it then? change DDR3 memory to DDR4? If you choose new computer Given future modernization, it would be useful to consider this possibility. Of course, we will then spend more initially, but this will make upgrading the computer easier in the future.

New type of memory modules

Minor changes have occurred in appearance memory module. True, its length and thickness are the same as in the case of DDR3, but an experienced eye will notice that the new modules are a millimeter taller and have 284 instead of 240 contacts.

In addition, the contacts in the central part of the module are higher than those at the edges. Thanks to this, installing memory requires less effort. The position of indents in the module has also changed. This procedure makes it impossible to place the memory in an unsuitable slot, such as one intended for installing DDR3 memory modules.

High speed DDR4

Currently, you can find mainly DDR3 memory on the market at frequencies of 1333 and 1600 M/s (million operations per second), and modules intended for enthusiasts reach frequencies of about 2400 or 2866 M/s.

In the case of DDR4, these parameters will be better, and operation at the level of 2400 M/s will become almost a standard. The JEDEC standard currently assumes the creation of DDR4 memory at speeds from 1600 to 3200 M/s, but modules at the 4166 M/s level have already been announced.

Long delays

Increasing memory speed always entails increasing latency, expressed in time cycles. A similar situation will happen this time. The JEDEC standard stipulates that the standard CAS latency for DDR4-2400 memory will be 15 cycles (for DDR3-1600 it was 10 cycles).

However, keep in mind that the delays do not actually change. To verify this, it is enough to make a simple calculation. A memory speed of 1600 M/s means its actual clock speed is 00 MHz. This means that one cycle lasts 1/800,000,0000 seconds. In this case, the delay expressed in 10 cycles is 12.5 nanoseconds. After performing the appropriate calculations for a 2400 M/s memory and 15 cycles, we get an identical result.

Large memory capacity

The largest DDR3 modules have a capacity of 8 GB. With DDR4 memory, a capacity of 32GB can easily be achieved. Assuming that a standard motherboard can accommodate four memory modules, this means that a computer equipped with 128GB of RAM will soon be a reality.

Performance difference

Even if there is a large difference in transfer speed between the two modules, in most programs there will be no or minimal change in performance.

See the benefits of using more fast memory will only be possible if you use the most demanding applications and games.

Less energy consumption

DDR3 requires a voltage of 1.5V, while DDR4 only requires 1.2V. According to manufacturers, this voltage change should provide energy savings of 30%. In practice, the savings are somewhat lower, however, thanks to the use of several innovations, it was possible to achieve the desired floor.

Some help included changing the signaling type and using DBI, that is, the memory bus inversion method. It lies in the fact that if in a particular data line most of the information consists of zeros, they are replaced by ones, and the dedicated controller perceives the data line as upside down.

Thanks to this, it is possible to switch transistors off and on more rarely, which reduces energy consumption and improves signal stability.

The appearance of DDR4 RAM on the market shook the unshakable position of its predecessor. It has higher technical characteristics and many users have a logical question, which RAM strip is better? Numerous tests and comparisons of fourth generation RAM with DDR3 show what the difference is between them. When choosing a DDR3 memory module, keep in mind that it is not compatible with DDR4.

A computer is one of the components that is responsible for its performance: the speed of information processing and the maximum amount of data processed in this moment. Until 2015, the first position was firmly held by third-generation DDR3 RAM, but with the advent of DDR4 the situation began to change towards the latest modification. The appearance of fourth-generation RAM caused a great stir in the computer equipment market, and at the same time a logical question arose, which is better than DDR3 or DDR4 and whether the appearance latest model a normal marketing ploy?

History of DDR4 development

JEDEK began developing fourth-generation RAM back in 2005, when the most modern modification was DDR2. The company's engineers already realized at that time that the second generation of RAM would not be able to meet the requirements of rapidly developing processors and other PC components. Even the announced release of third-generation RAM will not be able to fully cope with the task. To solve the problem, it is not enough to simply improve data processing speed, as was done in DDR3. It is necessary to take into account parameters such as power consumption and volume, which affect the throughput of the device.

Attention! To work with specialized programs: packages for three-dimensional design, photo or video editors, the main parameter for choosing RAM is its throughput, i.e. the speed of information processing.

In 2015, with the advent of Socket LGA1151 platforms on the market, PC users had the opportunity to produce comparative analysis Third and fourth generation RAM in the same conditions.

Specifications

Before you say that DDR3 or DDR4 is better and compare them, you should familiarize yourself in detail with their technical characteristics and capabilities, as well as their advantages and disadvantages. This approach will allow us to correctly and accurately determine the future of memory modules and identify a promising model.

DDR3

The main characteristics for RAM, regardless of its generation, are the following:

• Frequency. RAM of the third model is available with a frequency of 1066 MHz, 1333 MHz and 1600 MHz, and the latest modification has 1866 MHz. By overclocking the memory, its frequency can be increased to 2400 – 2666 MHz. The maximum value of this parameter during overclocking, which was obtained in laboratory conditions, is 4620 MHz.
• Voltage. Power consumption varies in the range of 1.5 – 1.8 V. Latest version DDR3L is capable of operating at a low voltage of 1.25 - 1.35 V. The L index means Low Power.
• Downtime. To determine the performance of a memory stick, one of the important parameters is timings or latency (CL), i.e. the delay in the transfer of information. DDR3 1600 MHz has a latency of 9 clock cycles; it takes 1 second to obtain the temporary value. divide by 1600 million clock cycles and we get 0.625 ms per clock cycle. We multiply the result by 9 clock cycles and get 5.625 ns. Next, we multiply by 2 (the number of data transmission streams) and the latency is 11.25 ns.

Advice. The latency value can be determined from the RAM markings after the letters CL. Accordingly, the lower its value, the higher the performance of the device.

DDR4

The fourth generation RAM has higher parameters technical characteristics, due to which it bypasses its predecessor.

Comparison of DDR3 and DDR4

Based on the technical characteristics, it is clear that the latency of DDR4 is higher than that of its predecessor. However, when reading data linearly or storing it due to practically unchanged timings, this difference is compensated, and the RAM of the fourth model wins. When working in multi-threaded mode, due to lower latency, DDR3 wins within the limits of statistical error. Performing file compression big size(volume from 1.5 GB and above), the time spent on the operation for DDR4 is 3% less than for DDR3. The third generation RAM specification provides for the use of Vddr voltage. When carrying out energy-intensive operations, it increases due to built-in converters, thereby generating abundant heat. The DDR4 module receives the required voltage from an external power supply (Vpp).

The RAM of the fourth model implements Pseudo-Open Draid technology, which made it possible to completely eliminate current leakage, which was observed in previous version, where Series-Stub Terminated Logic is used. Application of this interface for data input and output allowed to reduce energy consumption by up to 30%. As for the memory capacity of the DDR4 bar, the minimum value is 4 GB, and for DDR3 it is optimal because the maximum is 8 GB. The third generation RAM structure allows for up to 8 memory banks with a line length of 2048 bytes. The latest modification of RAM has 16 banks and a line length of 512 bytes, which increases the speed of switching between lines and banks.

From a comparison of DDR3 and DDR4 we can conclude that last generation RAM outperforms its predecessor in almost all respects, but this difference is hardly noticeable for regular user. DDR3L 1600 MHz combined with Intel Core i5 is almost as good as DDR4. It is recommended to install fourth generation RAM for modern games or work in specialized programs that require a large amount of memory and high speed data processing.

Comparison of DDR 3 and DDR 4 RAM: video