We destroy myths about the work of RAM. RAM frequency

Without exception, every computer or phone must have RAM. Without it, no computer device will function normally. Replacement random access memory- the first thing that comes to mind when it is necessary to increase the power and speed of the computer. Replacing the RAM is a very simple process that does not require any additional equipment... That is why many begin to improve their computer from this very element. system unit... Of course, you can change the processor or video card and this will give a greater performance gain. But unprepared person is unlikely to be able to choose and install a suitable processor himself. RAM is another matter. When buying it, you just need to know if the memory is compatible with motherboard... Let's see how to check compatibility.

Let's start with what RAM is. Random access memory, or RAM, is such a random access memory. It is a place of temporary storage of information with the help of which functions software, the computer itself. The RAM contains information that must be processed by the processor. In RAM, information is waiting for its turn.

Physically, RAM is a small bar on which the microcircuits are located. There are contacts on the bottom edge of the RAM, this side of the memory is inserted into the motherboard. Some, especially expensive, RAM models are equipped with a metal cooling radiator and backlight.

Interesting! RAM compares favorably with hard disk the fact that the number of operations and its age have practically no effect on durability. This means that high-quality RAM is a very reliable and durable device that will not fail for a long time. It is quite easy to break it by mechanical action, for example, if you insert it into the wrong slot.

Why you need to check the compatibility of the motherboard and RAM

It may seem like it doesn't matter what kind of RAM you put into your motherboard. It is not that simple. If you use the wrong RAM, your computer simply won't work. Otherwise, the RAM will not physically fit into the corresponding slot. If you buy the wrong memory stick, you will find yourself in a very unpleasant situation, because the RAM will either have to be changed or sold. In order not to get into this situation, let's find out how to choose the right RAM bar.

What is the difference between RAM

In order to understand how to choose RAM and how to check its compatibility with the motherboard, you need to understand how they differ from each other. different planks RAM. RAM differs in the following ways:

• memory type;
• manufacturer, a company that produces and sells a specific model;
• volume, the most important indicator, based on it, memory is selected;
• frequency.

Now let's take a closer look at each of these aspects. First of all, you should pay attention to the type of RAM. It can be: DDR2, DDR3, or DDR4. Of course, there are other types, but they are very outdated and there is no point in considering them now. All types of memory differ from each other not only in transmission speed, but also physically: different amounts contacts and different location"Key".

If you have a motherboard that supports only the DDR2 standard of RAM, then in no case should you insert other types of RAM into it. It will not physically go in there and will not work. Nevertheless, there are craftsmen who "modify" the RAM with a file or in any other way insert it into the wrong slot.

Manufacturer

Motherboards are not picky about the RAM manufacturer. Choose any manufacturer you like.

Memory

Motherboards have a limit on the maximum size of one module per slot. If you insert a module larger than the specified size, then the memory will not function correctly or will not work at all.

Frequency

An important indicator of compatibility. Each MP has a maximum frequency. While using faster RAM is unlikely to get a lot of power gain, fast RAM won't work with an outdated motherboard. Perhaps the memory will perform well at the lower frequency of the motherboard. But then there is no point in overpaying and buying fast RAM.

Compatibility check

It seems that RAM is very difficult to find due to the large number of requirements. But in reality, everything is not so scary, because you can use several simple and convenient methods.

Method one

Find out if your motherboard is compatible with the desired RAM on the manufacturer's website.

Method two

Find the motherboard box, paper instructions or instructions on the store's website. In it you will find all the characteristics of the motherboard, including the characteristics of the slots for RAM.

Third way

When buying RAM, contact a store consultant, he will help you choose memory based on your motherboard.

CPU and RAM compatibility

RAM control controller, in modern models installed directly into the processor. Now, when choosing memory, you still need to find out the compatibility with the processor. Fortunately, processors are not so demanding on RAM and in most cases work correctly with most modules. But some points are worth paying attention to. For example, Clarkdale Core i3, Core i5-6XX, Celeron G1XXX, Pentium G6XXX do not work with 512 MB chips.

Compatibility of RAM sticks from different manufacturers and frequencies

PC owners may want to increase the amount of RAM by purchasing a new module. They immediately have a question: "Will the new dies work correctly with the old ones?" In theory, everything should work, but in practice, problems arise.

The fact is that there are a lot of manufacturers of RAM, and there are only a few manufacturers of chips for this memory. Chips different manufacturers can be installed both on RAM from different manufacturers, and on different models RAM from the same manufacturer. That is, in theory, you can buy the same RAM from the same manufacturer, with a difference of several months or years, and the new die will have chips from a completely different manufacturer. Such dies may well have a conflict and they will not start.

On the other hand, you may be lucky and you will have several dies with different chips from different manufacturers working correctly. But memory differs not only in size and manufacturer, but also in frequency. Random access memory at different frequencies may well work together. At the same time, they will work at the frequency of the slowest RAM.

How to check RAM for errors

If you see abnormalities in your computer and suspect that RAM may be the culprit, then just check it for errors. This can be done in several ways.

Method 1.Using the standard Windows utility

Method 2. Using Memtest86 +

Memtest86 + is free program to test RAM for errors.

1. You can download the program from the official website.

   

2. Then you need to create a bootable USB flash drive with the Memtest86 + image. Run the downloaded file. Next, select the drive from the list.

   



After that, you need to wait a little while the installation is complete. Now you have an image of the program on your USB stick.

3. Enter the BIOS and set the boot mode there.

   

4. We reboot the computer, the program will start automatically and start checking itself.

   

5. No further action is required from you. You just have to wait until the end of the verification. All errors will be highlighted in red, so you won't be able to miss them.

   

6. Write down the error numbers, and later look on the Internet for what they mean. But unfortunately, if errors are found in your memory, then it is unlikely that it will already work correctly. The most simple solution this problem is the purchase of new RAM. If you do not want to buy new RAM, then try cleaning the contacts with an eraser or even warming up the RAM in the oven. It is not recommended to do this, because the memory can be damaged. However, many solve the problem with RAM errors just like that.

On a note! If you have several memory sticks installed, then run the scan for each of them one by one.

What to do if after installing new RAM a black screen

There are several obvious and not obvious reasons for this problem:

1. The new RAM is not supported by the motherboard. If the RAM is in the slot, but the computer does not work fully, then most likely the matter is in the frequency of the new memory. It is best to buy a new memory of the same frequency as the old one.

   

2. The reason for a non-working computer may be the incorrect voltage that is supplied to the RAM. DDR 3 RAM has several voltage options. It is rather difficult to make a mistake with the choice, because memory with low power consumption is denoted by the letter L. That is, the memory will be denoted as DDR3L.

   

3. If you are sure that the memory is selected correctly, then you may have inserted it into a broken slot. There are at least two RAM slots on the motherboard. Try to move the bracket to the adjacent slot and turn on the computer. The connector may have been physically damaged.

   

4. Gently remove the plate from the connector and look at its contacts. If they have black coating, dust, dirt, or other uncharacteristic build-up, then gently wipe the contacts with an eraser or plain sheet of paper. Many people decide to wipe the contacts with alcohol. Be aware that before returning the RAM to the slot, you must completely dry the alcohol from the contact surface. Otherwise, a short circuit may occur, which will permanently ruin your computer.

   

5. If all else fails, then the memory may be working properly, and the problem lies with the motherboard. To check this, you can insert memory or MP into another computer, and check the functionality there. If this is not possible, then remove all the RAM strips from the computer and turn it on. If the computer starts beeping - the sound of a lack of RAM, then the MP is fully operational. If there is complete silence after turning on the computer, then most likely the motherboard is faulty.

   

Checking the compatibility of components

Do not forget that for the computer to work correctly, all components must be fully compatible. Therefore, when assembling a PC, pay close attention to the compatibility of components. Do not be afraid to figure it out on your own and change or increase the RAM, because everyone can do it.

Video - How to choose RAM

If you open the catalog of an online store on a page with RAM, you can see hundreds different models memory with absolutely different characteristics... Such a wide selection is often confusing, especially for inexperienced users who want to choose RAM for their computer. If you are also confused by the variety of choices, then our step-by-step instruction should help you.

Step number 1. We select the RAM by type and connector.

The first thing to do when choosing RAM for your computer is to decide on the type of memory that you need. Modern computers use four types of memory:

• DDR is the very first version of DDR, now it is extremely rare;
• DDR2 is the second generation of DDR, found in older computers;
• DDR3 is the third generation of DDR, the most common variant on this moment;
• DDR4 is the most modern version DDR memory, found only in new computers;

In order to determine which of these types of RAM is used in your computer, run the CPU-Z program and open the "Memory" tab. The memory type, size, frequency and timings will be indicated here.

If you want to get more detailed information about each of the ramps installed in your memory, then go to the "SPD" tab.

In addition to the type of memory itself (DDR, DDR2, DDR3 and DDR4), it should be borne in mind that different slots are used for desktops and laptops. Desktop computers use DIMM slots and laptops use SO-DIMM slots. SO-DIMMs can also be used in compact desktop PCs.

Therefore, in order to be sure that the selected RAM will fit into the memory slot in the motherboard, it is necessary that the memory matches not only the type, but also the connector.

Step number 2. Select the desired frequency of the RAM.

After you have decided on the type and connector of RAM, you need to decide on the memory frequency that you need. There are several important points here:

• The memory frequency must be supported. This is usually not a problem. Since modern motherboards support a wide range of RAM frequencies. However, this needs to be checked. To do this, enter the name of your motherboard into the search engine and go to the website of its manufacturer. It will indicate which memory frequencies this board supports.
• Also the memory frequency must be supported. This is checked in the same way. Enter the processor name in the search and see the technical specifications on the manufacturer's official website. Processors are usually more severely limited in their maximum memory frequency.
• After that, determine the maximum frequency of RAM with which the motherboard and processor can work. This is the frequency you can use;

It should be noted that:

• You are not required to buy RAM with the maximum supported frequency. To save money, you can lower frequencies and everything will work. The main thing is that these frequencies are supported by the motherboard and processor.
• If the memory type is the same, then you can install the memory with higher frequencies. But, it will still work at the maximum allowable frequency for the motherboard and processor.
• You can install RAM with different frequencies, but it will work at the frequency of the slowest memory strip. Although it is not advisable to install different memory.

You also need to pay attention to the timings. There are no restrictions on the part of the motherboard or processor, but timings do affect performance. The lower the timings, the faster the memory.

Step number 3. Check the maximum amount of RAM and the availability of free slots on the motherboard.

One more important point, which you need to pay attention to when selecting RAM, this is the maximum amount that the motherboard and processor can support. On the website of the motherboard and processor manufacturer (in the same place where you looked at the frequencies), you need to see the maximum amount of RAM. Obviously, this volume cannot be exceeded.

You also need to check for free slots on the motherboard. To do this, you need to remove the side cover of the computer and inspect the board. The main thing is not to forget to completely disconnect the computer before doing this.

Step number 4. The final stage of selecting RAM for your computer.

It is advisable to always set the same RAM sticks. This avoids compatibility issues that, although very rare, do occur. Therefore, if possible, it is better to install the memory at once as a whole set.

If it is not possible to install the entire set of memory at once, then you need to choose the most similar memory. Find memory sticks with exactly the same characteristics as those installed in yours (compare the volume of one stick, frequencies, timings).

A computer is universal device, on which you can perform a huge number of tasks. Some users use its capabilities for study, others prefer to watch movies on their PC, and still others need powerful "machines" for games and professional activities. In each of these cases, you need to know how to choose the right RAM for a personal computer or laptop.

The performance and performance of the assembled system largely depends on this component. In this article, we will figure out which memory is better to buy depending on your needs and what you should pay attention to first of all.

Budget and memory requirements

The memory available on the market for a computer or laptop is very different in cost. The price of the planks is influenced by a huge number of parameters, including additional features such as radiators or customizable RGB lighting. As for the requirements, they depend on whether you collect new system or you are upgrading an existing one. For example, deciding to add RAM to a computer or laptop, you will need to select trims whose characteristics correspond to the parameters of the RAM installed in the PC. Experts often recommend even choosing the same manufacturer, but it is not necessary to follow this rule.

RAM selection criteria

When planning to add memory to an existing PC or wanting to purchase RAM for a new computer, you will surely come across a number of important criteria. Among them, the most important are frequency and timings. Also, the volume and number of strips included in the kit affects the performance of the system. The extra features of RAM usually have no practical benefit to the average user. So the backlight will be appropriate mainly for gaming PCs, where a similar feature is implemented in other components. Heatsinks, which were also mentioned above, may be required only for high-frequency RAM and compact assemblies, where problems with high-quality ventilation housing.

Memory types

Usually it is necessary to match the memory to the motherboard. There are 4 of them: the outdated DDR and DDR2, the still popular DDR3, capable of operating at frequencies up to 2400 MHz, as well as the most modern DDR4, the theoretical maximum of which is 4266 MHz.

Despite the fact that some stores still have stocks of DDR2 strips, it is almost impossible to find a motherboard for this type of RAM on sale. Only used versions of such boards are presented on the market, and new devices have not been released by manufacturers for a long time.

For the two remaining types, motherboards are offered in a wide range. But for gaming computer DDR4 RAM is a better choice as AMD's new Ryzen processors and Intel's Coffee Lake processors can unleash their full potential modern projects do not support DDR3 anymore.

However, you will not be able to install inappropriate RAM into your computer, because they are incompatible with each other due to the different number and location of contacts. For this reason, a motherboard with slots for DDR4 brackets does not support DDR3 and vice versa.

The only exceptions are motherboards, where it is possible to install both DDR3 and DDR4 memory at the same time. However, such solutions are rare and there is no point in buying them, because at the price both types of planks differ only slightly, when DDR4 exceeds its predecessor by several times in terms of parameters.

When buying memory for an office computer, you can stop at the DDR3 type. If you are building a powerful gaming PC, then purchase DDR4 trims to avoid frame loss.

Volume

Deciding how much memory to choose is based on the tasks that will be performed on the computer. So office systems aimed at working with text and surfing the Internet, it is enough to equip 2-4 GB. The volume from 4 to 8 GB must be installed already in multimedia and basic computers for games. But powerful gaming machines should be equipped with 16-32 GB of RAM. This amount of RAM is now enough for any modern project.

If you plan to take a larger amount of RAM for your computer, then this will be justified in two cases: a reserve for the future or specialized tasks. It is likely that in 2-3 years there will already be games that require 24 or more RAM for stable operation at high graphics settings. If during this or a longer period you will not update the PC, then you can immediately take the appropriate trims. Also, 32 or more gigabytes of RAM will be required to run professional programs.

You also need to take into account the bitness and version of the system that is installed on your computer. So 32-bit Windows will not see more than 4 GB of RAM, and if we are talking about Windows 7 Starter, then it can only work with 2 gigabytes. At the same time, 64-bit operating systems use about twice as much RAM for their needs, which must also be taken into account when assembling the system.

The maximum version of Windows 7 can work with 192 gigabytes of RAM, and professional Windows versions 8 and 10 already support up to 512 GB. You can find out the exact information about the amount of RAM that can be installed in your system on the official Microsoft website.

If you install more memory in your computer than the operating system installed on it supports, then the "extra" amount will simply not be used.

Which frequency to choose

As is the case with processors or graphics adapters, the frequency of the RAM determines its speed. The higher this indicator, the better performance the PC will show. However, you should not immediately run after the most advanced RAM in the store. Before buying, you need to make sure that the selected option is supported by the motherboard and processor.

Of course, if you buy memory that is better in performance than what your hardware can open, then there will be nothing wrong with that. When such brackets are installed in a computer, they will simply start operating at the maximum frequency supported by the system. But the disadvantage in this case will be higher costs, because good RAM at 3000 MHz will cost more than its counterpart from the same series at 2400 MHz.

Again, look for bars whose frequency matches maximum values supported by your computer is also not worth it. Enough for office tasks simple models at 1333 MHz (DDR3) or at 2133 MHz (DDR4). A balanced solution for a wide range of tasks will be 2400 or 2666 MHz RAM. But progressive gaming PCs and professional assemblies are already better equipped with RAM at 3000-3600 MHz and more.

Intel's XMP technology and its AMD counterpart AMP allow high-frequency RAM to work at its maximum capacity even if the declared frequency is not supported by the processor. However, this technology must be implemented not only in the "stone" itself, but also in the motherboard, which automatically raises its price.

Timings

This parameter in the characteristics is indicated by a number-letter (for example, CL15) or numeric (15-17-17-35) designation. Both in the first and in the second case, we are talking about the delay of the RAM between the execution of various operations. If you want to choose the right RAM, then this parameter must be addressed Special attention, because at high timings and high frequencies, you will get about the same performance as in low-frequency RAM with low latencies.

For the DDR3 type, CL9 will be excellent timings, and in slower models that are popular on the market, this parameter is equal to CL11. The standard delays in DDR4 strips are CL15, and in cheaper memory modules you can see CL16 or CL17 timings. For this type of RAM, you can find lower delays, but they are extremely rare on sale.

Note. CL corresponds to the first number in the block of digits. So the above numerical designation of timings 15-17-17-35 can be written as CL15.

Important! It is not recommended to buy RAM with high timings. From the reviews on such memory on the forums, you can understand that it has poor performance and significantly degrades the performance of the PC.

Modes of operation

Many users forget that not only the choice of the amount of RAM is important, but also the number of bars from which it is dialed. This is due to the fact that in modern computers, RAM operates in a multichannel mode, which significantly increases the performance of the system in professional applications, demanding games and other tasks. If you install one 16 GB memory module in your computer or laptop, you will get worse performance than if you choose a pair of 8 GB sticks.

In total, 4 modes of RAM operation are allocated today:

1. Single channel.
2. Two-channel.
3. Three-channel.
4. Four-channel.

The first is considered obsolete and is present only in older PCs. Its essence lies in the fact that all data is written sequentially to each module, regardless of their total amount. Modern computers can work in this mode if the user has installed only one bar of RAM.

Most issued for last years the motherboard works in two-channel mode. However, there are also boards on sale with support for three- and four-channel configurations. However, the cost of such models is quite high, and the advantage of the indicated modes can not always be noticed.

It should be borne in mind that the two-channel mode works when using 2 or 4 memory sticks, the three-channel mode - 3 or 6, and the four-channel mode - 4 or 8. Another important nuance is the need to install modules with the same volume, frequency, timings and other parameters.

However, if the characteristics of the strips do not match, then this will not affect the performance (with the exception of voltage). At different frequencies the system will be able to operate at the frequency of the slowest module. A similar rule applies to timings. If the volumes in the PC do not match, the multichannel mode will simply not work.

The Flex option is also worth noting. It allows you to deviate from this rule and use memory sticks of different sizes for the two-channel mode. In this case, the matching volumes will be used in two-channel mode, and the remaining one - in single-channel mode. For example, when choosing modules for 8 and 4 GB, 4 gigabytes from each bracket will work in dual-channel mode, while the remaining 4 GB from the first module can operate in single-channel mode.

When buying, you need to take into account that one RAM module will cost a little cheaper than a set of strips with the same parameters and the same total volume. However, purchasing all strips separately from each other will cost you a lot. large amount... Therefore, if you have a sufficient budget, it is better to immediately purchase a kit of the required volume.

Important! Flex Mode is not supported by all motherboards, so before choosing RAM for expansion, you should read the instructions for your board.

Form Factor

Also, from the characteristics of memory modules, the form factor is important for users. It can be DIMM or SO-DIMM. The first are standard PC strips, on which, depending on the type, can be located from 168 to 240 contacts. SO-DIMM form factor stands for laptop or computer memory small size motherboards which are in Mini-ITX format. On such strips, there are from 72 to 200 contacts.

Supply voltage

This characteristic is especially important when choosing an additional memory strip for a PC or laptop. Despite the fact that most modern boards operate at standard voltage (2.5V for DDR, 1.8V for DDR2, 1.5V for DDR3, 1.2V for DDR4), solutions for enthusiasts with increased power supply and models with reduced power are also on sale. Install incompatible software in the PC this parameter straps are strictly prohibited, because unstable operation of the RAM is possible (if the strap does not receive enough voltage) or even its failure (when the RAM is supplied with a higher power than it needs to work).

Before purchasing an additional RAM module for your computer, first make sure that the power it requires matches the voltage of the RAM installed in your PC.

Deciphering the marking of random access memory

For marking any type of strips, standard designations are used, including the letters PC and a number indicating the transfer rate in Mb / s (bandwidth). But it is not very convenient for an ordinary user to navigate by them, because it is much more convenient to know the frequency and timings.

Usually the seller indicates all the information about the memory, but if you are picking up used RAM on the classifieds site, then an inexperienced user may well indicate something like PC2-8500. This means that we have DDR2 RAM with a frequency of 1066 MHz and CL5 timings.

DDR3 strips are designated PC3:

• 10600 - 1333 MHz;
• 12800 - 1600 MHz;
• 14400 - 1866 MHz;
• 16000 - 2000 MHz.

In the first case, the timings are CL9, and in the other three CL11.

DDR4 strips are marked, respectively, by PC4:

• 17000 - 2133 MHz;
• 19200 - 2400 MHz;
• 21300 - 2666 MHz;
• 24000 - 3000 MHz;
• 25600 - 3200 MHz.

For the first type of memory, the latency is usually CL15, and for others - CL16.

Which company to buy RAM modules

Speaking about which RAM to choose, it is also necessary to mention its manufacturers. This market has its own undisputed leaders with extensive experience and factories equipped with the latest technology. Famous brands guarantee that the planks you have purchased will be able to serve for many years without breakdowns and failures. If you want to get high quality RAM and have a sufficient amount of funds, then you should take a closer look at the following popular manufacturers of RAM modules:

1. Kingston.
2. Crucial.
3. Corsair.
4. G.Skill.
5. GOODRAM.

With a limited amount of money allocated for RAM, budget firms such as Team Group and AMD are also excellent choices, offering excellent value for money for their memory.

Try to avoid little-known and inexperienced RAM manufacturers, even if they offer a very "tasty" price. Also read the reviews of the memory kits you are interested in before purchasing them.

Output

Modern PCs can perform a myriad of tasks, from processing photos and playing movies to running modern games and demanding graphics programs. And if simple tasks can be executed on simple hardware, then "heavy" applications require a powerful processor, a modern video card and, ultimately, fast RAM. You can choose for your computer thanks to our detailed recommendations... If you have any questions, we will always be happy to answer them. Enjoy the shopping!

Then it will not be possible to replace it with a newer and more advanced DDR4 - along with the memory, you will have to change the motherboard and processor. When assembling a new computer, the most current type of memory is recommended - DDR4.

Memory

It is recommended to install at least 4 GB of RAM in a modern computer. The standard now is 8 GB - this volume is enough for the user for most everyday tasks. A professional who often works in "heavy" programs such as Autocad and 3DSMax is recommended to install modules of 16 GB and higher.

Memory is often sold in sets of two, four or more modules. Two modules with the same parameters, inserted into the motherboard slots of the same color, will operate in "dual channel mode" - this will give an increase in data transfer speed and increase the speed of the system and applications.

Clock frequency

The memory clock speed determines the rate at which data is exchanged with the motherboard. The higher the frequency, the faster the computer runs. The memory bandwidth and the module price directly depend on it. You need to choose memory based on what frequencies are supported by the motherboard and processor.

Form Factor

Most home computers use the DIMM form factor. SODIMM format memory is most often installed on laptops. The rest of the form factors are unlikely to be of interest to the common user - they are installed either on servers or on old PCs.

My compliments to dear visitors of the site. In the last article I wrote about. Now, having learned what it is and what it is for and how it serves, many of you are probably thinking about purchasing a more powerful and productive RAM for your computer. After all, increasing computer performance with additional memory RAM is the simplest and cheapest (as opposed to, for example, a video card) method of upgrading your pet.

And ... Here you are standing at a display case with packages of RAM. There are many of them and they are all different. Questions arise: What kind of RAM to choose?How to choose the right RAM and not miscalculate?What if I buy a RAM, and then it will not work? These are reasonable questions. In this article I will try to answer all these questions. As you already understood, this article will take its rightful place in a series of articles in which I wrote about how to choose the right individual components of a computer, i.e. iron. If you haven't forgotten, it included articles:
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This cycle will be continued further, and at the end you will be able to assemble for yourself a super computer perfect in every sense 🙂 (if, of course, finances allow :))
Until then learning to choose the right memory for your computer.
Go!

Random access memory and its main characteristics.

When choosing RAM for your computer, you must definitely build on your motherboard and processor, because the RAM modules are installed on the motherboard and it also supports certain types of RAM. Thus, the relationship between the motherboard, processor and RAM is obtained.

Learn about what kind of RAM does your motherboard and processor support? can be found on the manufacturer's website, where you need to find the model of your motherboard, as well as find out what processors and RAM for them it supports. If this is not done, then it turns out that you bought a super modern RAM, but it is not compatible with your motherboard and will gather dust somewhere in your closet. Now let's go directly to the main technical characteristics of RAM, which will serve as a kind of criteria when choosing RAM. These include:

Here I have listed the main characteristics of RAM, which are worth paying attention to first of all when buying it. Now we will open each of them in turn.

RAM type.

Today the most preferred type of memory in the world is memory modules DDR(double data rate). They differ in release time and, of course, in technical parameters.

• DDR or DDR SDRAM(translated from English. Double Data Rate Synchronous Dynamic Random Access Memory - synchronous dynamic memory with random access and double data rate). Modules of this type have 184 contacts on the bar, are powered by a voltage of 2.5 V and have a clock frequency of up to 400 megahertz. This type of RAM is already morally outdated and is used only in old motherboards.
• DDR2 Is a widespread type of memory at this time. Has 240 pins on the printed circuit board (120 on each side). Consumption, unlike DDR1, is reduced to 1.8 V. The clock frequency ranges from 400 MHz to 800 MHz.
• DDR3- the leader in productivity at the time of this writing. It is not less widespread than DDR2 and consumes 30-40% less voltage than its predecessor (1.5 V). Has a clock frequency of up to 1800 MHz.
• DDR4- a new, super modern type of RAM, which is ahead of its counterparts both in performance (clock frequency) and voltage consumption (which means it has a lower heat dissipation). Support for frequencies from 2133 to 4266 MHz is announced. At the moment, these modules have not yet entered mass production (they promise to release them into mass production in mid-2012). Officially, fourth generation modules operating in DDR4-2133 at 1.2 V were presented at CES, by Samsung 04 January 2011

The amount of RAM.

I will not write much about the amount of memory. I will only say that it is in this case that size matters 🙂
All a few years ago, 256-512 MB of RAM satisfied all the needs of even cool gaming computers. At present, for normal functioning, only operating system windows 7 requires 1GB of memory, not to mention applications and games. There will never be extra RAM, but I'll tell you a secret that 32-bit windows uses only 3.25 GB of RAM, even if you install all 8 GB of RAM. You can read more about this.

The dimensions of the strips or the so-called Form factor.

Form - factor- these are the standard sizes of the RAM modules, the type of construction of the RAM strips themselves.
DIMM(Dual InLine Memory Module - double-sided type modules with contacts on both sides) - mainly intended for desktop stationary computers, and SO-DIMM used in laptops.

Clock frequency.

This is pretty important technical parameter random access memory. But the motherboard also has a clock frequency and it is important to know the operating frequency of the bus of this board, since if you bought, for example, a RAM module DDR3-1800, and the slot (connector) of the motherboard supports the maximum clock frequency DDR3-1600, then the RAM module as a result will operate at a clock frequency of 1600 MHz... In this case, all sorts of failures, errors in the operation of the system, etc., are possible.

Note: Memory bus frequency and processor frequency are completely different concepts.

From the above tables, it can be understood that the bus frequency multiplied by 2 gives the effective memory frequency (indicated in the "chip" column), i.e. gives us the baud rate. The name also tells us about it. DDR(Double Data Rate) - which means double data transfer rate.
For clarity, I will give an example of decoding in the name of the RAM module - Kingston / PC2-9600 / DDR3 (DIMM) / 2Gb / 1200MHz, where:
- Kingston- manufacturer;
- PC2-9600- the name of the module and its bandwidth;
- DDR3 (DIMM)- type of memory (form factor in which the module is made);
- 2Gb- the volume of the module;
- 1200MHz- effective frequency, 1200 MHz.

Bandwidth.

Bandwidth Is a memory characteristic that affects system performance. It is expressed as the product of the system bus frequency by the amount of data transmitted per clock cycle. Bandwidth (Peak Data Rate) is a complex measure of capability RAM, it takes into account data transmission frequency, bus width and the number of memory channels. Frequency indicates the potential of the memory bus per clock cycle - higher frequencies can transfer more data.
The peak indicator is calculated using the formula: B = f * c, where:
B - bandwidth, f - transmission frequency, c - bus width. If you use two channels for data transmission, we multiply everything received by 2. To get the figure in bytes / s, you need to divide the result by 8 (since there are 8 bits in 1 byte).
For better performance RAM bus bandwidth and processor bus bandwidth must match. For example, for an Intel core 2 duo E6850 processor with a 1333 MHz system bus and a bandwidth of 10600 Mb / s, you can install two modules with a bandwidth of 5300 Mb / s each (PC2-5300), in total they will have throughput system bus (FSB) equal to 10600 Mb / s.
Bus frequency and bandwidth are designated as follows: " DDR2-XXXX" and " PC2-YYYY". Here "XXXX" stands for the effective memory frequency and "YYYY" for the peak bandwidth.

Timings (latency).

Timings (or latency) Are the time delays of the signal, which, in technical characteristics RAM is written as " 2-2-2 " or " 3-3-3 " etc. Each digit here represents a parameter. In order, it is always “ CAS Latency"(Working cycle time)," RAS to CAS Delay"(Full access time) and" RAS Precharge Time"(Pre-charge time).

Note

So that you can better understand the concept of timings, imagine a book, it will be our RAM, which we refer to. Information (data) in a book (RAM) is divided into chapters, and chapters consist of pages, which in turn contain tables with cells (as in Excel spreadsheets). Each cell with data on the page has its own coordinates vertically (columns) and horizontally (rows). The RAS (Raw Address Strobe) signal is used to select a row, and the CAS (Column Address Strobe) signal is used to read a word (data) from the selected row (i.e., to select a column). Full cycle reading begins with the opening of the "page" and ends with its closing and reloading, because otherwise the cells will be discharged and the data will disappear. This is how the algorithm for reading data from memory looks like:

1. the selected "page" is activated by the RAS signal;
2. data from the selected line on the page is transmitted to the amplifier, and a delay is required for data transmission (it is called RAS-to-CAS);
3. a CAS signal is given to select (column) a word from this row;
4. data is transferred to the bus (from where it goes to the memory controller), while there is also a delay (CAS Latency);
5. the next word goes without delay, since it is contained in the prepared line;
6. after the call to the row is completed, the page is closed, the data is returned to the cells and the page is recharged (the delay is called RAS Precharge).

Each digit in the designation indicates how many bus clock cycles the signal will be delayed. Timings are measured in nano seconds. The numbers can range from 2 to 9. But sometimes a fourth is added to these three parameters (for example: 2-3-3-8), called “ DRAM Cycle Time Tras / Trc”(Characterizes the speed of the entire memory chip as a whole).
It happens that sometimes a cunning manufacturer indicates only one value in the characteristics of the RAM, for example, “ CL2"(CAS Latency), the first timing is equal to two clock cycles. But the first parameter does not have to be equal to all timings, and maybe less than others, so keep this in mind and do not fall for the manufacturer's marketing ploy.
An example for clarity of the effect of timings on performance: a system with memory at a frequency of 100 MHz with timings 2-2-2 has approximately the same performance as the same system at a frequency of 112 MHz, but with delays of 3-3-3. In other words, depending on latency, the difference in performance can be up to 10%.
So, when choosing, it is better to buy memory with the lowest timings, and if you want to add a module to the already installed one, then the timings of the purchased memory must match the timings of the installed memory.

Memory operation modes.

The RAM can work in several modes, if, of course, such modes are supported by the motherboard. it single-channel, two-channel, three-channel and even four-channel modes. Therefore, when choosing RAM, you should pay attention to this parameter of modules.
Theoretically, the speed of the memory subsystem in the dual-channel mode increases by 2 times, in the three-channel mode - 3 times, respectively, etc., but in practice, in the dual-channel mode, the performance gain, in contrast to the single-channel mode, is 10-70%.
Let's take a closer look at the types of modes:

• Single chanell mode(single-channel or asymmetric) - this mode is enabled when only one memory module is installed in the system or all modules differ from each other in terms of memory size, operating frequency, or manufacturer. It doesn't matter in which slots and memory to install. All memory will run at the speed of the slowest memory installed.
• Dual Mode(dual-channel or balanced) - the same amount of RAM is installed in each channel (and theoretically, the maximum data transfer rate doubles). In dual-channel mode, memory modules work in pairs: 1st with 3rd and 2nd with 4th.
• Triple Mode(three-channel) - the same amount of RAM is installed in each of the three channels. Modules are selected in terms of speed and volume. To enable this mode, modules must be installed in slots 1, 3 and 5 / or 2, 4 and 6 slots. In practice, by the way, this mode is not always more productive than the two-channel mode, and sometimes even loses to it in the data transfer rate.
• Flex Mode(flexible) - allows you to increase the performance of the RAM when installing two modules of different sizes, but the same frequency of operation. As in the dual-channel mode, memory cards are installed in slots of the same name on different channels.

Usually the most common option is dual channel memory.
To work in multichannel modes, there are special sets of memory modules - the so-called Kit memory(Kit-set) - this kit includes two (three) modules, of the same manufacturer, with the same frequency, timings and memory type.
Appearance of KIT-kits:
for two-channel mode

for three-channel mode

But the most important thing is that such modules are carefully selected and tested, by the manufacturer itself, for operation in pairs (triplets) in two- (three-) channel modes and do not imply any surprises in operation and configuration.

Module manufacturer.

Now on the market RAM manufacturers such as: Hynix, amsung, Corsair, Kingmax, Transcend, Kingston, OCZ…
Each company has its own product for each product. marking number, according to which, if you decipher it correctly, you can learn a lot for yourself useful information about the product. For example, let's try to decipher the labeling of the module. Kingston families ValueRAM(see image):

Decoding:

• KVR- Kingston ValueRAM i.e. manufacturer
• 1066/1333 - working / effective frequency (Mhz)
• D3- memory type (DDR3)
• D (Dual) - rank / rank... A dual-rank module is two logical modules soldered on the same physical channel and alternately using the same physical channel (needed to achieve the maximum amount of RAM with a limited number of slots)
• 4 - 4 DRAM memory chips
• R - Registered, indicates stable operation without failures or errors for as long as possible a continuous period of time
• 7 - signal delay (CAS = 7)
• S- thermal sensor on the module
• K2- a set (kit) of two modules
• 4G- the total volume of the whale (both planks) is 4 GB.

I will give another example of marking CM2X1024-6400C5:
The marking shows that it is DDR2 module volume 1024 MB standard PC2-6400 and delays CL = 5.
Stamps OCZ, Kingston and Corsair recommended for overclocking, i.e. have the potential for overclocking. They will be with small timings and a margin clock frequency Plus, they are equipped with heatsinks, and some even coolers for heat dissipation. during acceleration, the amount of heat increases significantly. The price for them will naturally be much higher.
I advise you not to forget about fakes (there are a lot of them on the shelves) and buy RAM modules only in serious stores that will give you a guarantee.

Finally:
That's all. With the help of this article, I think you can no longer make a mistake when choosing RAM for your computer. Now you can choose the right RAM for the system and increase its performance without any problems. Well, for those who buy RAM (or have already bought it), I will devote the following article, in which I will describe in detail how to properly install RAM into the system. Do not miss…