Marking of Samsung memory modules. RAM details
Publication date:
25.06.2009
As you know, RAM contributes a large component to the performance of a computer. And it is clear that users are trying to increase the amount of RAM to the maximum.
If 2-3 years ago there were literally several types of memory modules on the market, now there are much more of them. And it became more difficult to understand them.
In this article we will look at the various symbols in the marking of memory modules to make it easier for you to navigate them.
First, let's introduce a number of terms that we will need to understand the article:
- strip ("die") - memory module, printed circuit board with memory chips on board, installed in a memory slot;
- one-sided strip - a memory strip in which the memory chips are located on 1 side of the module.
- double-sided stick - a memory stick in which memory chips are located on both sides of the module.
- RAM (Random Access Memory, RAM) - random access memory, in other words - random access memory. This is a volatile memory whose contents are lost when power is lost.
- SDRAM (Synchronous Dynamic RAM) - synchronous dynamic random access memory: all modern memory modules have just such a device, that is, they require constant synchronization and content updates.
Consider the markings
- 4096Mb (2x2048Mb) DIMM DDR2 PC2-8500 Corsair XMS2 C5 BOX
- 1024Mb SO-DIMM DDR2 PC6400 OCZ OCZ2M8001G (5-5-5-15) Retail
Volume
The first designation in the line is the size of the memory modules. In particular, in the first case it is 4 GB, and in the second case it is 1 GB. True, 4 GB in in this case implemented not by one memory stick, but by two. This is the so-called Kit of 2 - a set of two planks. Typically, such kits are purchased to install strips in two-channel mode into parallel slots. The fact that they have the same parameters will improve their compatibility, which has a beneficial effect on stability.
Type of shell
DIMM/SO-DIMM is a type of memory stick housing. All modern memory modules are available in one of the two specified designs.
DIMM(Dual In-line Memory Module) - a module in which the contacts are arranged in a row on both sides of the module.
DDR SDRAM memory is available in the form of 184-pin DIMM modules, and 240-pin strips are available for DDR2 SDRAM memory.
Laptops use smaller memory modules called SO-DIMM(Small Outline DIMM).
Memory type
Memory type is the architecture by which the memory chips themselves are organized. She affects everything specifications memory - performance, frequency, supply voltage, etc.
On this moment 3 types of memory are used: DDR SDRAM, DDR2 SDRAM, DDR3 SDRAM. Of these, DDR3 is the most productive and consumes the least energy.
Data transfer frequencies for memory types:
- DDR: 200-400 MHz
- DDR2: 533-1200 MHz
- DDR3: 800-2400 MHz
The number indicated after the memory type is frequency: DDR400, DDR2-800.
Memory modules of all types differ in supply voltage and connectors and cannot be inserted into each other.
The data transfer frequency characterizes the potential of the memory bus to transfer data per unit time: the higher the frequency, the more data can be transferred.
However, there are other factors, such as the number of memory channels and memory bus width. They also affect the performance of memory subsystems.
For a comprehensive assessment of RAM capabilities, the term is used throughput memory. It takes into account the frequency at which data is transmitted, the bus width and the number of memory channels.
Bandwidth (B) = Frequency (f) x memory bus width (c) x number of channels (k)
For example, when using DDR memory 400-400 MHz and dual-channel memory controller bandwidth will be:
(400 MHz x 64 bit x 2)/ 8 bit = 6400 MB/s
We divided by 8 to convert Mbit/s to MB/s (there are 8 bits in 1 byte).
Memory module speed standard
To make it easier to understand the speed of the module, the designation also indicates the standard of memory bandwidth. It just shows how much bandwidth the module has.
All of these standards begin with the letters PC and are followed by numbers indicating memory bandwidth in MB per second.
| Module name | Bus frequency | Chip type | |
| PC2-3200 | 200 MHz | DDR2-400 | 3200 MB/s or 3.2 GB/s |
| PC2-4200 | 266 MHz | DDR2-533 | 4200 MB/s or 4.2 GB/s |
| PC2-5300 | 333 MHz | DDR2-667 | 5300 MB/s or 5.3 GB/s 1 |
| PC2-5400 | 337 MHz | DDR2-675 | 5400 MB/s or 5.4 GB/s |
| PC2-5600 | 350 MHz | DDR2-700 | 5600 MB/s or 5.6 GB/s |
| PC2-5700 | 355 MHz | DDR2-711 | 5700 MB/s or 5.7 GB/s |
| PC2-6000 | 375 MHz | DDR2-750 | 6000 MB/s or 6.0 GB/s |
| PC2-6400 | 400 MHz | DDR2-800 | 6400 MB/s or 6.4 GB/s |
| PC2-7100 | 444 MHz | DDR2-888 | 7100 MB/s or 7.1 GB/s |
| PC2-7200 | 450 MHz | DDR2-900 | 7200 MB/s or 7.2 GB/s |
| PC2-8000 | 500 MHz | DDR2-1000 | 8000 MB/s or 8.0 GB/s |
| PC2-8500 | 533 MHz | DDR2-1066 | 8500 MB/s or 8.5 GB/s |
| PC2-9200 | 575 MHz | DDR2-1150 | 9200 MB/s or 9.2 GB/s |
| PC2-9600 | 600 MHz | DDR2-1200 | 9600 MB/s or 9.6 GB/s |
| Memory type | Memory frequency | Cycle time | Bus frequency | Data transfers per second | Standard name | Peak Data Rate |
| DDR3-800 | 100 MHz | 10.00 ns | 400 MHz | 800 million | PC3-6400 | 6400 MB/s |
| DDR3-1066 | 133 MHz | 7.50 ns | 533 MHz | 1066 million | PC3-8500 | 8533 MB/s |
| DDR3-1333 | 166 MHz | 6.00 ns | 667 MHz | 1333 million | PC3-10600 | 10667 MB/s |
| DDR3-1600 | 200 MHz | 5.00 ns | 800 MHz | 1600 million | PC3-12800 | 12800 MB/s |
| DDR3-1800 | 225 MHz | 4.44 ns | 900 MHz | 1800 million | PC3-14400 | 14400 MB/s |
| DDR3-2000 | 250 MHz | 4.00 ns | 1000 MHz | 2000 million | PC3-16000 | 16000 MB/s |
| DDR3-2133 | 266 MHz | 3.75 ns | 1066 MHz | 2133 million | PC3-17000 | 17066 MB/s |
| DDR3-2400 | 300 MHz | 3.33 ns | 1200 MHz | 2400 million | PC3-19200 | 19200 MB/s |
The tables indicate exactly the peak values; in practice they may be unattainable.
Manufacturer and its part number
Each manufacturer gives each of its products or parts its internal production marking, called P/N (part number).
For memory modules different manufacturers it looks something like this:
- Kingston KVR800D2N6/1G
- OCZ OCZ2M8001G
- Corsair XMS2 CM2X1024-6400C5
On the website of many memory manufacturers you can study how their Part Number is read.
Modules Kingston ValueRAM family:
Kingston HyperX family modules (with optional passive cooling for overclocking):
From the OCZ marking you can understand that this is a 1 GB DDR2 module with a frequency of 800 MHz.
By labeling CM2X1024-6400C5 It is clear that this is a 1024 MB DDR2 module of the PC2-6400 standard and CL=5 delays.
Some manufacturers indicate the time in ns of access to the memory chip instead of the frequency or memory standard. From this time you can understand what frequency is used.
This is what Micron does: MT47H128M16HG-3. The number at the end indicates that the access time is 3 ns (0.003 ms).
According to the well-known forum T=1/f frequency of the chip f=1/T: 1/0.003 = 333 MHz.
The data transmission frequency is 2 times higher - 667 MHz.
Respectively, this module DDR2-667.
Timings
Timings are delays when accessing memory chips. Naturally, the smaller they are, the faster the module works.
The fact is that the memory chips on the module have a matrix structure - they are presented in the form of matrix cells with a row number and a column number.
When accessing a memory cell, the entire line in which the desired cell is located is read.
First there is a choice the desired line, then the desired column. At the intersection of the row and column number the desired cell is located. Taking into account the huge volume of modern RAM, such memory matrices are not integral - for more quick access to memory cells they are divided into pages and banks.
First, the memory bank is accessed, the page in it is activated, then work takes place within current page: Select row and column.
All these actions occur with a definitely delay relative to each other.
Basic RAM timings are the delay between supplying the row number and column number, called time full access (RAS to CAS delay, RCD), the delay between supplying the column number and receiving the contents of the cell, called duty cycle time ( CAS latency, CL), delay between reading the last cell and submitting the number new line (RAS precharge, RP). Timings are measured in nanoseconds (ns).
These timings follow each other in the order of operations and are also indicated schematically 5-5-5-15 . In this case, all three timings are 5 ns, and the total duty cycle is 15 ns from the moment the line is activated.
The main timing is considered CAS latency, which is often abbreviated CL=5. It is he who “slows down” memory to the greatest extent.
Based on this information, you can wisely select the appropriate memory module.
RAM is a special chip used to store data of all kinds. There are many varieties of these devices, they are produced various companies. The best manufacturers Most often they are of Japanese origin.
What is it and what is it for?
RAM (so-called RAM memory) is a type of volatile chip used to store all kinds of information. Most often it contains:
- machine code of programs currently running (or in standby mode);
- input and output data.
Photo: RAM from different manufacturers
Data exchange between the central processor and RAM is carried out in two ways:
- using ultra-fast register ALU;
- through special cache(if included in the design);
- directly (directly via the data bus).
The devices in question are circuits built on semiconductors. All information stored in various electronic components, remains available only if available electric current. As soon as the voltage is completely turned off, or a short-term power failure occurs, then everything contained inside the RAM is erased or destroyed.
An alternative is ROM type devices.
Types and amount of memory Today the board can have a capacity of several tens of gigabytes. Modern 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 its size, the more expensive it is. And vice versa.
Also, the devices in question may have different frequencies. This parameter determines how quickly the interaction between RAM and other PC devices (CPU, data bus and video card) occurs. The higher the operating speed, 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 current fastest modification can “remember” 128 GB. It is produced by a company called Hynix and has the following performance characteristics:
All modern RAM can be divided into two types:
- static;
- dynamic.
Static type
More expensive today is the static microcircuit. It is labeled as SDRAM. Dynamic is cheaper.
Distinctive features of the SDRAM variety are:
Also distinctive feature RAM is the ability to select the bit into which any information will be written.
The disadvantages include:
- low recording density;
- relatively high cost.
Computer RAM devices of all kinds (SDRAM and DRAM) have external differences. They consist in the length of the contact part. Its shape also differs. The designation of RAM is both on the sticker label and printed directly on the bar itself.
Today there are many different modifications of SDRAM. It is designated as:
- DDR 2;
- DDR 3;
- DDR4.
Dynamic type
Another type of microcircuit is referred to as DRAM. It is also completely volatile, the write bits are accessed randomly. This type is widely used in most modern PCs. It is also used in those computer systems, where latency requirements are high, the performance of DRAM is an order of magnitude higher than SDRAM.
DRAM - dynamic memory
Most often, this type has the form factor DIMM type. The same design solution is used to manufacture a static circuit (SDRAM). A feature of the DIMM version is that there are contacts on both sides of the surface.
OP parameters
The main criteria for choosing microcircuits of this type are their operating parameters.
You should primarily focus on the following points:
- frequency of operation;
- timings;
- voltage.
They all depend on the type specific model. For example, DDR 2 will perform various actions clearly faster than the DDR 1 bar, since it has more outstanding performance characteristics.
Timings are the time delays for information between various components devices. There are quite a few types of timings, all of them directly affect performance. Small timings allow you to increase execution speed various operations. There is one unpleasant proportional relationship - the higher the speed of the random access memory device, the greater value timings.
Exit from this provision serves to increase the operating voltage - the higher it is, the shorter the timings become. The number of operations performed per unit of time increases at the same time.
Frequency and speed
The higher the RAM bandwidth, the faster its speed. Frequency is a parameter that determines the bandwidth of the channels through which various types of data are transmitted to the CPU through the motherboard.
It is advisable that this characteristic coincided with the permissible operating speed motherboard.
For example, if the bracket supports a frequency of 1600 MHz, and the motherboard supports no more than 1066 MHz, then the speed of data exchange between the RAM and the CPU will be limited precisely by the capabilities of the motherboard. That is, the speed will be no more than 1066 MHz.
Performance
Performance depends on many factors. Very big influence on this parameter influences the number of strips used. Dual-channel RAM works an order of magnitude faster than single-channel RAM. The ability to support multi-channel modes is indicated on a sticker located on top of the board.
These designations are as follows:
To determine which mode is optimal for a particular motherboard, you need to count the total number of connection slots and divide them by two. For example, if there are 4 of them, then you need 2 identical strips from the same manufacturer. With them parallel installation Dual mode is activated.
Working principle and functions
The operation of the OP is implemented quite simply; writing or reading data is carried out as follows:
Each column is connected to an extremely sensitive amplifier. It records the flow of electrons that occurs when the capacitor is discharged. In this case, the corresponding command is given. Thus, access to various cells located on the board occurs. There is one important nuance which you should definitely know. When an electrical impulse is applied to any line, it opens all its transistors. They are connected to it directly.
From this we can conclude that one line is the minimum amount of information that can be read when accessing. The main purpose of RAM is to store various types of temporary data that are necessary while Personal Computer turned on and functioning operating system. The most important ones are loaded into RAM executable files
The CPU executes them directly, simply storing the results of the operations performed.
Photo: interaction of memory with processor
- The cells also store:
- executable libraries;
- key codes that were pressed;
results of various mathematical operations. If necessary, everything that is in RAM can be stored by the central processor. HDD
. And do it in the form in which it is necessary.
Manufacturers You can find it in stores great amount RAM from a wide variety of manufacturers. A large number of
Such products began to be supplied precisely from Chinese companies.
- Today, the most productive and high-quality products are the following brands:
- Kingston;
- Hynix;
- Corsair;
- Kingmax.
Samsung.
It is a compromise between quality and performance.
Table of RAM characteristics RAM one type from various manufacturers
has similar performance characteristics.
That is why it is correct to carry out comparisons taking into account only the type:
Performance and price comparison
The performance of RAM directly depends on its cost. You can find out how much a DDR3 module costs at your nearest computer store; you should also check out the price of DDR 1. By comparing their operating parameters and price, and then testing them, you can easily verify this. It is most correct to compare RAM of the same type, but with different performance
| , depending on the frequency of operation: | Type | Operating frequency, MHz | Cost, rub.Speedwork, Aida 64, |
| Memory Read, MB/s | 1333 | 3190 | 19501 |
| Memory Read, MB/s | 1600 | 3590 | 22436 |
| Memory Read, MB/s | 1866 | 4134 | 26384 |
| Memory Read, MB/s | 2133 | 4570 | 30242 |
| Memory Read, MB/s | 2400 | 6548 | 33813 |
| Memory Read, MB/s | 2666 | 8234 | 31012 |
| Memory Read, MB/s | 2933 | 9550 | 28930 |
DDR 3
- In Aida 64, all DDR 3 tests were performed on identical hardware:
- OS: Windows 8.1;
- CPU: i5-4670K; video card: GeForce GTX
- 780 Ti;
motherboard: LGA1150, Intel Z87. RAM is very important PC, greatly affecting its performance. That is why, to increase it, it is recommended to install levels with high frequencies and short timings. This will give a big boost to your computer's performance; it is especially important for games and various professional programs.
Every time you look under the cover of the system unit case, you can see strips consisting of microcircuits and chips. They even resemble cartridges for old console"Sega". However, their purpose is completely different. Further in the article it will be given detailed description markings of RAM and its devices.
Random access memory is temporary storage of data on a computer. Its task is to download the requested data from its storage and leave it there in encrypted form. When the user requests the information again, the RAM will produce the result faster, since the original material has already been stored. This is the operating principle on which the decoding of RAM markings depends.
The most important indicators of RAM are frequency and timing. The operating frequency shows the speed at which data is transferred. This parameter is measured in megahertz (abbr. MHz or MHz).
Timing is responsible for delaying time. That is, it shows how much time RAM needs to process the request and produce the result.
Form factors
In other words, this parameter can be called size standardization. There are two types of RAM marking form factors - DIMM and SoDIMM.
The first format is suitable exclusively for desktop computers. This can be seen by looking at the connector on the motherboard. The length of this slot reaches almost 13.35 cm. Each strip is secured with latches on the sides. Due to the length, the number of contacts increases. This is what the RAM DIMM marking means.
With the SoDIMM form factor, things are a little different. Firstly, the size - this format is designed to work in laptops or miniITX motherboards. The length of this strip is 67.6 mm. This size is justified by the fact that laptop computers limited internal space, and this forces us to make components smaller size. This RAM marking is for a laptop, not a standard computer.
However, the difference in size does not affect the technical characteristics at all - laptops simply have a less demanding system than desktop computers.
Memory types
IN modern computers There are two types of memory used - DDR3 and DDR4.
DDR3 RAM has minimum frequency at 1033 MHz. And its “overclocking” frequency reaches 1600 MHz. This type of memory was first put into operation after 2010. It was from the third generation that it became possible to use RAM as a backup for integrated graphics processors.
In the case of DDR4 RAM markings, the initial frequency indicators are 1333 MHz. The "overclocking" potential makes it possible to increase the operating frequency to 2600 MHz with short timings. Its advantages are not only higher frequencies, but also lower power consumption. The increase from 240 to 288 contacts had no effect on the size of the bar.
Using the example of DDR3L RAM markings, it can be noted that it differs from its twin DDR3.
The prefix at the end means Low, that is, low. This is justified by the fact that this type RAM uses a lower input voltage. Its indicator is 1.35 Volts. On regular ones it is 1.5 V. This parameter allows you to reduce power consumption by 10%. Co standard RAM third generation they look exactly the same.
Compatibility
The first experiment in the symbiosis of two generations of RAM was not very successful. It's about about DDR2 and DDR3, or more precisely, about motherboards that had both types of RAM slots. However, the use different types RAM did not produce any results. As a result, the motherboard could only recognize one type of memory.
As for DDR3 and DDR3L, things are a little simpler here. They have some compatibility - motherboards with DDR3 connectors can support DDR3L RAM. But there is no backward compatibility, since motherboards with DDR3L connectors are designed to operate at low voltage.
The differences between the third and fourth generations are obvious - the location of the gap at the contacts is in a different place. You won't even be able to fit the module into the slot.
This type RAM is top-end for gaming computers, as it has an “overclocking” profile and high frequencies. Almost all modern motherboards that were released after 2015 support DDR4.
Many manufacturers have begun to equip memory modules with various software profiles, cooling systems, and even backlighting. IN modern games The amount of RAM plays an important role. Therefore, along with the new generation came increased RAM sizes. At the moment, one stick can have a capacity of up to 64 GB. However, new RAM costs a lot of money - this is the only drawback.
How to install a module in a system unit
Before starting installation, you should pay attention to the RAM labeling. An example is shown in the photo below. Now it’s time to find out the parameters central processor, which are associated with RAM. The fact is that not every processor can unleash the potential of RAM. And not every processor will be able to support the overclocking profile.
Installing one strip will not take much time. To do this, you will need to remove the cover of the system unit and move the latches on the motherboard. All manipulations with motherboard are held only in horizontal position so as not to damage the components. Next, the strip is placed in the connector and secured with latches.
After this, you need to put everything back together and start the computer. Without waiting for the operating system to load, you need to call up the BIOS menu to make sure that the plate is detected and functioning normally.
To work in dual-channel mode, it is better to purchase modules in pairs, since they are tested together, which has a positive effect on working together. If the second and subsequent strips are purchased separately, then you should pay attention to their indicators - frequencies and timings.
How to install RAM in a laptop
Installing memory modules in a laptop is slightly different from a similar operation in a desktop version. To do this you will need a screwdriver to unscrew the screws on back cover laptop computer.
Before starting the installation, it is worth clarifying a few nuances. Firstly, on all laptops you can install no more than two slots (some have only one slot). Secondly, the installation of two strips is carried out exclusively in pair mode, since modules from different manufacturers cause a conflict. Before work, you must unplug the laptop and remove the battery.
Now you need to unscrew the bolts securing the cover that covers the RAM. If a module is replaced, the old one must be removed. If the volume increases, you just need to find out if there is a free connector. Please note that most modern laptop models will have to be completely disassembled to get to the module installation slot.
The installation method resembles the process of installing a cassette into a tape recorder - a laptop has a similar slot. Next, the bar is placed in a free slot and you need to gently press it until a characteristic click is heard, which means that the module is locked.
After assembly, you can connect the laptop to the network and start the system. If the operating system is working properly, then the laptop recognizes the installed RAM.
Hello, friends! In this article, we tried to answer many of your questions regarding RAM. ? How can I find out what RAM I have installed and how much? How to choose the right RAM for your computer. How do you know if your RAM is running in dual channel mode or not? What is better to buy, one 8GB DDR3 memory stick or two 4GB sticks each? And finally.
- If you are interested, or, also read our articles.
- Hello admin, one of my friends asks me to install more RAM. The computer properties show a capacity of 2 GB. Turned off the computer, opened system unit, there is one stick of RAM, we took it out, and there were no marks on it. Interestingly, it was not possible to determine the model of the motherboard. The computer was purchased a long time ago, so the question arose - how to find out the type of RAM it needs? After all, RAM differs in type, frequency and timing.
- Hi all! I wanted to buy additional RAM, I removed the cover of the system unit, took out the RAM stick and I can’t decipher the information written on it, it’s just written there serial number that's all. It is completely unclear at what frequency it operates and what type it is, DDR3 or DDR2. How to distinguish DDR3 memory from DDR2, how do they differ in appearance?
- I have one stick of 4 GB DDR3-1600 RAM in the system unit, I want to install another stick, also 4 GB, but running at a higher frequency DDR3-1866. Will my computer work normally, and most importantly, in dual-channel mode?
My friend installed three RAM sticks of different sizes and frequencies into the system unit. Is this allowed? But what’s strange is that his computer works fine! - Tell me, how can I check if my RAM is working in dual-channel mode or not? And what conditions are needed for my memory to work in dual-channel mode. Same volume? Same frequency or same timings? How much faster does a computer run in dual-channel mode than in single-channel mode? They say that there is also a three-channel mode.
- What will work better, two sticks of 4 GB of RAM in dual-channel mode or one stick, but with a capacity of 8 GB, respectively, the memory mode will be single-channel?
To find out all the information about a RAM module, you need to carefully examine it; usually the manufacturer labels the RAM with the proper information about the frequency, volume and type of RAM. If there is no such information on the module, then you need to find out everything about the motherboard and installed processor, Sometimes this action turns into a whole investigation.
- Important Notes: Friends, do not forget that all new processors Intel Core i3, Intel Core i5, Intel Core i7 The RAM controller is located in the processor itself (previously it was controlled by north bridge motherboards) and memory modules are now directly controlled by the processor itself, the same applies to latest processors AMD.
- This means that it doesn't matter what RAM frequency your motherboard supports. It is important what RAM frequency your processor supports. If your computer has a processorIntel Core i3, Intel Core i5, Intel Core i7, then the officially supported memory standards of these processors: PC3-8500 (DDR3-1066 MHz), PC3-10600 (DDR3-1333 MHz), PC3-12800 (DDR3-1600 MHz), it is at these frequencies that your RAM will operate, even if the motherboard's passport indicates that the motherboard can work with RAM strips high frequency PC3-19200 (DDR3-2400 MHz).
- It's another matter if your processor has unlocked multiplier, that is, with the letter “K” at the end, for example CPU Intel Core i7-4770 K, 3.5 GHz. An unlocked multiplier means that in a computer with such a processor you can install memory sticks of the highest frequency, for example DDR3-1866 MHz or DDR3-2400 MHz, such a processor can be overclocked and during overclocking the RAM will operate at its frequency of 2400 MHz . If you install the RAM stick DDR3-1866 MHz or DDR3-2400 MHz into a computer with regular processor, that is, with locked multiplier without letter" K” at the end, for exampleIntel Core i7-3770, 3.9 GHz then such a bar will work in best case scenario at frequency DDR3-1600 MHz, and in the worst case, the computer will not boot. Therefore, buy RAM that is suitable for your processor.
- Concerning processorsAMD recent years, then they work with memoryPC3-10600 (DDR3-1333 MHz).
Firstly, the RAM stick itself should contain all the information you are interested in, you just need to read it correctly. I don’t argue, there are memory strips that have practically nothing on them, but we can handle them too.
For example, let’s take a Hynix RAM stick, it has the following information: 4 GB PC3 – 12800.
What does the following mean:
firstly, the volume is 4 GB,
secondly, 1Rx8 - Rank - a memory area created by several or all chips of a memory module, 1Rx8 are single-sided memory ranks, and 2Rx8 are double-sided memory ranks.
As you can see, this bar does not say that it is DDR2 or DDR3, but the throughput of PC3-12800 is indicated. PC3 is a designation for peak bandwidth belonging only to the DDR3 type (for DDR2 RAM the designation will be PC2, for example PC2-6400).
This means that our Hynix RAM stick is DDR3 and has PC3-12800 bandwidth. If the bandwidth of 12800 is divided by eight and you get 1600. That is, this DDR3 memory stick operates at a frequency of 1600 MHz.
Read everything about DDR2 and DDR3 RAM on the website
http://ru.wikipedia.org/wiki/DDR3 and everything will become clear to you.
Let's take another RAM module - Crucial 4GB DDR3 1333 (PC3 - 10600). This means the following: volume 4 GB, memory type DDR3, frequency 1333 MHz, PC3-10600 bandwidth is also indicated.
Manufacturer Patriot, capacity 1 GB, PC2 bandwidth – 6400. PC2 is a designation for peak bandwidth belonging only to the DDR2 type (for DDR3 RAM the designation will be PC3, for example PC3-12800). We divide the bandwidth of 6400 by eight and get 800. That is, this DDR2 memory stick operates at a frequency of 800 MHz.
One more plank- Kingston KHX6400D2 LL/1G
Manufacturer Kingston, bandwidth 6400, type DDR2, capacity 1 GB. We divide the bandwidth by 8, we get a frequency of 800 MHz.
But this stick of RAM has more important information
, its microcircuit supply voltage is non-standard: 2.0 V - set manually in the BIOS.
RAM modules differ in the size of the contact pads and the location of the cutouts. Using a cutout, you will not be able to install a RAM module in a slot not intended for it. For example, you cannot install a DDR3 memory stick in a DDR2 slot.
Everything is clearly visible in this diagram.
Sometimes the RAM module will not have any clear information, except for the name of the module itself. But the module cannot be removed, since it is under warranty. But by the name you can understand what kind of memory it is. For example
Kingston KHX1600 C9D3 X2K2/8G X, all this means:
KHX 1600 -> RAM operates at 1600 MHz
C9 -> Timings (Delays) 9-9-9
D3 -> RAM type DDR3
8G X -> Volume 4 GB.
You can simply type the name of the module in search engines and you will find out all the information about it.
For example, information from the AIDA64 program about my RAM. Kingston HyperX RAM modules are installed in RAM slots 2 and 4, memory type DDR3, frequency 1600 MHz
DIMM2: Kingston HyperX KHX1600C9D3/4GX DDR3-1600 DDR3 SDRAM
DIMM4: Kingston HyperX KHX1600C9D3/4GX DDR3-1600 DDR3 SDRAM
Is it possible to install RAM sticks with different frequencies into a computer?
The RAM frequency does not have to be the same. The motherboard will set the frequency for everyone installed strips RAM according to the slowest module. But I want to say that often a computer with brackets different frequencies works unstable.
Let's do a simple experiment. For example, let's take my computer, it has two identical Kingston HyperX RAM modules, memory type DDR3, frequency 1600 MHz.
If I run the AIDA64 program on my Windows 8, it will show the following information (see the following screenshot). That is, the program AIDA64 shows simple technical characteristics of each RAM stick; in our case, both sticks have a frequency1600 MHz. But the programAIDA64 does not show at what frequency the RAM modules are currently operating; this needs to be looked at in another program called CPU-Z.
If you launch a free CPU-Z program and go to the Memory tab, it will show you exactly what frequency your RAM sticks operate at. My memory works in dual channel Dual mode, frequency 800 MHz, since the memory is DDR3, its effective (double) speed is 1600 MHz. This means that my RAM sticks operate exactly at the frequency for which they are designed: 1600 MHz. But what will happen if next to your RAM strips operating at a frequency 1600 MHz I will set another bar with frequency 1333 MHz!?
Let's install an additional DDR3 memory stick in my system unit, operating at a lower frequency of 1333 MHz.
Let's see what AIDA64 shows, the program shows that it is installed additional bar 4 GB capacity, frequency 1333 MHz.
Now let’s run the CPU-Z program and see at what frequency all three sticks operate. As we can see, the frequency is 668.7 MHz, since the memory is DDR3, its effective (double) speed is 1333 MHz.
That is, the motherboard automatically set the operating frequency of all RAM sticks to the slowest module at 1333 MHz.
It is not advisable to install RAM sticks in your computer with a frequency higher than what the motherboard supports. For example, if your motherboard supports maximum frequency RAM is 1600 MHz, and you installed a RAM module on your computer operating at a frequency of 1866, then in the best case this module will operate at a lower frequency of 1600 MHz, and in the worst case the module will operate at its own frequency 1866 MHz, but the computer will periodically reboot itself or you will receive when you boot your computer blue screen, in this case you will have to enter the BIOS and manually set the RAM frequency to 1600 MHz.
Timings(signal delay) determine how often the processor can access RAM if you have quad-core processor and it has a large second-level cache, then too long timings are not a problem, since the processor accesses RAM less often. Is it possible to install RAM sticks with different timings into a computer? The timings also do not have to match. The motherboard will automatically set timings for all modules according to the slowest module.
What conditions are needed for my memory to work in dual-channel mode? Before buying RAM, you need to study as much information as possible about the motherboard. All information about your motherboard can be found in the manual that came with it upon purchase. If the manual is lost, you need to go to the official website of your motherboard. You will also find the article “How to find out the model and all information about your motherboard” useful.Most often these days there are motherboards that support the RAM operating modes described below. Dual Mode (two-channel mode, most common)– if you look closely at the motherboard, you can see that the RAM slots are painted in different colors. This was done on purpose and means that the motherboard supports dual-channel RAM operation. That is, two RAM modules with the same characteristics (frequency, timings) and the same volume are specially selected and installed in RAM slots of the same color.
If your computer has one stick of RAM installed, but the motherboard supports dual-channel mode, you can buy an additional stick of RAM of exactly the same frequency and capacity and install both sticks in DIMM slots of the same color.
Is there an advantage to dual channel mode over single channel mode?
At regular work on a computer you won’t notice the difference, but when working in applications that actively use RAM, for example Adobe Premiere Pro (video editing), (Canopus) ProCoder (video encoding), Photoshop (working with images), games, you can feel the difference.
Note: Some motherboards will operate in dual-channel mode even if you install RAM modules of different sizes in the same color DIMM slots. For example, you will install a 512MB module in the first DIMM slot, and a 1GB stick in the third slot. The motherboard activates dual-channel mode for the entire volume of the first 512MB stick, and for the second stick (interestingly) also 512MB, and the remaining 512MB of the second stick will work in single-channel mode.
How do I know if my RAM is working in dual channel mode or not? Download free program CPU-Z and go to the Memory tab, look at the Channel parameter in our case - Dual, which means the RAM operates in dual-channel mode. If the Channels parameter is Single, then the RAM operates in single-channel mode.
My opinion is that during normal work on a computer they will work the same, I personally didn’t notice much of a difference. I worked for a long time on a computer with one large stick of RAM and the performance was the same as on exactly the same computer with two sticks of RAM running in dual-channel mode. A survey of friends and acquaintances of system administrators confirmed me in this opinion. But when working with programs that actively use RAM, for example Adobe Premiere Pro, Canopus ProCoder, Photoshop, games, a computer with two sticks of RAM will work faster.
Of course it is possible, but not advisable. The computer will work more stable if it implements the RAM operating mode recommended in the motherboard datasheet. For example, two-channel mode.
