The role of RAM in a computer. What is random access memory (RAM)

RAM capacity

Next, let’s take a closer look at the next important characteristic of RAM – its volume. First, it should be noted that it most directly affects the number of simultaneously running programs, processes and applications and their uninterrupted operation. Today, the most popular modules are sticks with a capacity of 4 GB and 8 GB (we are talking about the DDR3 standard).

Based on what operating system is installed, as well as for what purposes the computer is used, you should choose and select the right amount of RAM. For the most part, if the computer is used to access the World Wide Web and to work with various applications, and Windows XP is installed, then 2 GB is quite enough.

For those who like to try out a recently released game and people who work with graphics, you should install at least 4 GB. And if you plan to install Windows 7, you will need even more.

The easiest way to find out how much memory your system requires is to launch the Task Manager (by pressing the keyboard combination ctrl+alt+del) and launch the most resource-consuming program or application. After this, you need to analyze the information in the “Memory Allocation” - “Peak” group.

In this way, you can determine the maximum allocated volume and find out to what volume it needs to be increased so that our highest indicator fits in RAM. This will give you maximum system performance. There will be no need to increase further.

Selecting RAM

Now let's move on to the question of choosing the RAM that is most suitable for you. From the very beginning, you should determine exactly the type of RAM that your computer's motherboard supports. There are different connectors for different types of modules, respectively. Therefore, to avoid damage to the motherboard or the modules themselves, the modules themselves have different sizes.

The optimal amounts of RAM were discussed above. When choosing RAM, you should focus on its bandwidth. For system performance, the most optimal option is when the module throughput matches the same characteristics of the processor.

That is, if the computer has a processor with a 1333 MHz bus, the bandwidth of which is 10600 MB/s, then to ensure the most favorable conditions for performance, you can install 2 strips, the bandwidth of which is 5300 MB/s, and which in total will give us 10600 Mb/s

However, it should be remembered that for this mode of operation, the RAM modules must be identical in both volume and frequency. In addition, they must be manufactured by the same manufacturer. Here is a short list of well-proven manufacturers: Samsung, OCZ, Transcend, Kingston, Corsair, Patriot.

Finally, it is worth summarizing the main points:

• Based on the definition: random access memory or RAM is a component of a computer necessary for temporary storage of data, which in turn is necessary for the processor to operate.
• After completing any operations (closing programs, applications), all associated data is deleted from the chip. And when new tasks are launched, the data that the processor needs at a given time is loaded into it from the hard drive.
• The speed of access to data located in RAM is several hundred times higher than the speed of access to information located on the hard drive. This allows the processor to use the information it needs, gaining instant access to it.
• Today, the most common 2 types are: DDR3 (with a frequency from 800 to 2400 MHz) and DDR4 (from 2133 to 4266 MHz). The higher the frequency, the faster the system operates.

If you have difficulty choosing RAM, if you cannot determine what type of RAM your motherboard supports and what volume will best suit your needs, then you can always contact the service website. We are computer help at home in Moscow and the Moscow region. Our specialists will help with selection, replacement and installation in a computer or laptop.

RAM

Purpose and basic ideas about the operation of computer functional blocks

Memory device (memory) - ϶ᴛᴏ one of the basic functional units of any computer.

In modern computers, memory is represented by two types of memory:

- basic(operational) memory (OP),

- external ( VP).

RAM designed for storage current information. It stores all utility and application programs that serve the computing process, initial and intermediate data, and the result of calculations.

RAM volatile. This means that when the computer's power is turned off, all information in RAM is lost.

This memory is represented by many microcircuits (LSI), which contain a large number of on-off elements ( triggers), amounting to tens and hundreds of millions. Two-position element - it is an element that can only be in one of two possible states. This is the basic element of all modern computers. It was agreed to designate one state of the element as ʼʼ0ʼʼ, and the other as ʼʼ1ʼʼ. Such elements are very reliable and easy to implement. With the help of two-position elements, all information in the computer is represented. In this case, any text or numeric information is displayed as combinations of ʼʼ0ʼʼ and ʼʼ1ʼʼ, that is encoded or, as they also say, it appears in machine codes. This code is also called binary code, because it uses two characters.

Any information has a size or quantity, that is, it should be little or much. To measure information, a unit of measurement was adopted.

Per unit of measurement amount of information one of the states of the on-off element is accepted. This unit was called b, etc. Information that a two-position element is in the ʼʼ0ʼʼ or ʼʼ1ʼʼ state and is information of size one bit. In RAM, all elements of information (symbols, numbers) are stored in I h e k a h. A cell is a small area of ​​memory. Cells come in different sizes based on the type of information stored in them. Each cell has its own address. The address of a cell is its serial number.
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The minimum cell size is taken to be its size, determined by eight adjacent two-position elements. A cell of this size is usually called one byte. In Fig. Figure 2.1 shows a diagram of such a cell.

Rice. 2.1 One byte cell

Such a cell can store 2 = 256 information options. That is, 256 different combinations of 0 and 1. The number of such cells is usually used to measure the size of memory, or as they say Memory . The memory capacity of one byte is the minimum unit of its measurement. But this is a very small unit; therefore, other larger units were adopted.

1 KB (kilobyte) = 2 bytes = 1024 bytes;

1 MB (megabyte) = 2 KB = 1024 KB = 2 bytes;

1 GB (gigabyte) = 2 MB = 1024 MB = 2 bytes.

1 TB (terabyte) = 2 GB = 1024 GB = 2 40 bytes.

It should be remembered that RAM only stores current information. When the computer is turned off, information is lost. The RAM itself has several sections (zones).

The main amount of memory is allocated to the area in which you can read and write information without any restrictions. This area is called About the operational memory device (RAM). It has random access to cells. This access allows you to receive data at any address and in any order.

Another area of ​​RAM is PERMANENT MEMORING DEVICE (ROM). Its contents can be just read and no running program can change it. This information is always unchanged and constantly available, incl. and when the computer is turned on. The ROM contains the program for booting the computer when it is turned on. Under loading understand the creation of copies of various programs or data in RAM, the originals of which are located on any external storage media (hard drive, floppy disks, CDs, etc.). ROM contains the minimum necessary programs that are entered into it by the computer manufacturer. These include programs for testing the most important functional units when the computer is turned on (memory, keyboard, display, etc.). These are BIOS input/output system programs ( Basic Inpu t Output Ssystem). Recently, it has become possible for the consumer himself to enter the necessary information into ROM by placing a “clean” ROM chip in a special device called programmer . Today, ROM chips have appeared that allow them to be reprogrammed several times. Οʜᴎ are called PROM ( P reprogrammable P permanent h reminiscent at buildings). One of the latest PROM designs is flash memory .

According to the method of implementing two-position elements, memory is distinguished:

- s t a t i c h e s k u u,

- d i n a m i c h e s k u .

Static memory is implemented on the basis of transistor on-off elements, triggers . These elements have two stable states and can remain in any of them for as long as desired.

Dynamic memory is implemented on the basis of two-position elements, the base of which uses capacitors. A logical one corresponds to a charged capacitor, and a logical zero corresponds to an uncharged one. A significant disadvantage of dynamic memory is the gradual discharge of capacitors through external circuits, which leads to loss of information. To prevent this from happening, it is extremely important to periodically recharge dynamic memory capacitors. This process is called R e g e n e r a t i o n RAM.

Today, increasing preference is given to dynamic memory, as it is easier to manufacture, takes up less space and is cheaper. It should be noted that semiconductor memory production technology is constantly being improved. This gives rise to the emergence of new memory chips. In modern computers, the amount of RAM reaches several tens of GB.

2.2. Cache - memory

There is a contradiction between fast, but more expensive static memory and worse performance, but cheaper dynamic memory. A reasonable compromise for building cost-effective and efficient systems is to use an intermediate k e sh - p a m i t i. This type of memory appeared relatively recently. Starting with the 486th processor, all computer models are equipped with cache memory.

The cache is a small, fast static memory that serves to speed up access to slow dynamic memory.

The basic idea of ​​how cache memory works is that data or program commands extracted from RAM are copied into the cache. At the same time, in a special directory of addresses, which is located in the same memory, the address from where the information was extracted is stored. If the data is required again, there will be no need to waste time accessing RAM. They can be obtained from cache memory much faster.

Since the volume of cache memory is significantly less than the volume of RAM, the cache memory controller closely monitors which data should be saved and which data is extremely important to replace. Information that is used less frequently or is not used at all is deleted. The controller also ensures timely replacement of changed data from cache memory back to RAM.

In modern computers, cache memory is implemented at two levels:

- first,

- second.

First the memory level is built directly into the processor, and second installed on the system board. As with RAM, increasing the amount of cache memory increases the efficiency of the computer.

Working memory - concept and types. Classification and features of the "RAM" category 2017, 2018.

A lot of computer users often wonder what RAM is. To help our readers understand RAM in detail, we have prepared material in which we will look in detail at where it is can be used and what are his types are now in use. We will also look at a little theory, after which you will understand what modern memory is.

A little theory

The abbreviation RAM stands for - random access memory. Essentially, it is the RAM that is primarily used in your computers. The operating principle of any type of RAM is based on storing information in special electronic cells. Each cell is 1 byte in size, meaning it can store eight bits of information. Each electronic cell has a special address. This address is needed so that you can access a specific electronic cell, read and write its contents.

Also, reading and writing to an electronic cell must be carried out at any time. In the English version, RAM is RAM. If we decipher the abbreviation RAM(Random Access Memory) - random access memory, then it becomes clear why the cell is read and written at any time.

Information is stored and rewritten in electronic cells only when your PC works, after turning it off, all information that is in RAM is erased. The totality of electronic cells in a modern RAM can reach a volume from 1 GB to 32 GB. The types of RAM currently in use are called DRAM And SRAM.

• First, DRAM is dynamic RAM, which consists of capacitors And transistors. The storage of information in DRAM is determined by the presence or absence of charge on the capacitor (1 bit of information), which is formed on the semiconductor crystal. To store information, this type of memory requires regeneration. Therefore this slow and cheap memory.
• Second, SRAM is Static RAM. The principle of cell access in SRAM is based on a static flip-flop, which includes several transistors. SRAM is an expensive memory, so it is used mainly in microcontrollers and integrated circuits, in which the memory capacity is small. This fast memory, not requiring regeneration.

Classification and types of SDRAM in modern computers

The most common type of DRAM memory is synchronous memory SDRAM. The first subtype of SDRAM is DDR SDRAM. DDR SDRAM memory modules appeared in the late 1990s. At that time, computers based on Pentium processes were popular. The image below shows a 512 MB DDR PC-3200 SODIMM stick from GOODRAM.

Console SODIMM means that the memory is intended for laptop. In 2003, DDR SDRAM was replaced by DDR2 SDRAM. This memory was used in modern computers of that time until 2010, until it was replaced by the next generation of memory. The image below shows a 2 GB DDR2 PC2-6400 stick from GOODRAM. Each generation of memory demonstrates increasingly faster data exchange speeds.

The DDR2 SDRAM format was replaced in 2007 by an even faster DDR3 SDRAM. This format remains the most popular to this day, although a new format is breathing behind it. The DDR3 SDRAM format is now used not only in modern computers, but also in smartphones, Tablet PCs And budget video cards. DDR3 SDRAM is also used in game consoles Xbox One eighth generation from Microsoft. This set-top box uses 8 gigabytes of DDR3 SDRAM format RAM. The image below shows a 4 GB DDR3 PC3-10600 memory from GOODRAM.

In the near future, the DDR3 SDRAM memory type will be replaced by a new type DDR4 SDRAM. After which DDR3 SDRAM will face the fate of previous generations. Mass release of memory DDR4 SDRAM started in the second quarter of 2014, and it is already used on motherboards with a CPU socket Socket 1151. The image below shows the format bar DDR4 PC4-17000 4 gigabytes from GOODRAM.

DDR4 SDRAM bandwidth can reach 25,600 Mb/s.

How to determine the type of RAM in a computer

You can very easily determine the type of RAM that is in a laptop or desktop computer using the utility CPU-Z. This utility is absolutely free. Download CPU-Z available from its official website www.cpuid.com. After downloading and installing, open the utility and go to the " SPD" The image below shows the utility window with the "tab" open. SPD».

In this window you can see that the computer on which the utility is open has RAM type DDR3 PC3-12800 4 gigabytes from Kingston. In the same way, you can determine the type of memory and its properties on any computer. For example, below is a window CPU-Z with RAM DDR2 PC2-5300 512 GB from Samsung.

And in this window there is a window CPU-Z with RAM DDR4 PC4-21300 4 GB from ADATA Technology.

This verification method is simply irreplaceable in a situation where you need to check for compatibility the memory you are planning to purchase for RAM expansion your PC.

Selecting RAM for a new system unit

To select RAM for a specific computer configuration, we will describe below an example that shows how easy it is to select RAM for any PC configuration. For example, we'll take this latest configuration based on an Intel processor:

• CPU- Intel Core i7-6700K;
• Motherboard- ASRock H110M-HDS on Intel H110 chipset;
• Video card- GIGABYTE GeForce GTX 980 Ti 6 GB GDDR5;
• SSD- Kingston SSDNow KC400 1000 GB;
• power unit- Chieftec A-135 APS-1000C with a power of 1000 W.

To select RAM for this configuration, you need to go to the official page of the ASRock H110M-HDS motherboard - www.asrock.com/mb/Intel/H110M-HDS.

On the page you can find the line “ Supports DDR4 2133”, which states that a RAM with a frequency of 2133 MHz is suitable for the motherboard. Now let's go to the menu item " Specifications" on this page.

In the page that opens you can find the line “ Max. capacity of system memory: 32GB", which states that our motherboard supports up to 32 gigabytes of RAM. From the data we received on the motherboard page, we can conclude that for our system, an acceptable option would be this type of RAM - two DDR4-2133 16 GB PC4-17000 memory modules.

We specifically indicated two 16 GB memory modules, and not one 32 GB, because two modules can operate in dual-channel mode.

You can install the above modules from any manufacturer, but these RAM modules are best suited. They are presented on the official page for the motherboard in the paragraph “ Memory Support List", since their compatibility has been verified by the manufacturer.

The example shows how easily you can find out information about the system unit in question. In the same way, RAM is selected for all other computer configurations. I would also like to note that using the configuration discussed above, you can run all the latest games with the highest graphics settings.

For example, on this configuration new games such as Tom Clancy's The Division, Far Cry Primal, Fallout 4 and many others, since such a system meets all the realities of the gaming market. The only limitation for this configuration is that it price. The approximate price of such a system unit without a monitor, including two memory modules, a case and the components described above, will be about 2000 dollars.

Classification and types of SDRAM in video cards

New video cards and older models use the same type of synchronous SDRAM memory. In new and outdated video card models, this type of video memory is most often used:

• GDDR2 SDRAM - bandwidth up to 9.6 GB/s;
• GDDR3 SDRAM - bandwidth up to 156.6 GB/s;
• GDDR5 SDRAM - bandwidth up to 370 GB/s.

To find out the type of your video card, the amount of RAM and memory type, you need to use a free utility GPU-Z. For example, the image below shows the program window GPU-Z, which describes the characteristics of the video card GeForce GTX 980 Ti.

GDDR5 SDRAM, which is popular today, will be replaced in the near future by GDDR5X SDRAM. This new classification of video memory promises to increase bandwidth up to 512 GB/s. The answer to the question of what manufacturers want to achieve from such a large throughput is quite simple. With the advent of formats such as 4K and 8K, as well as VR devices, the performance of current video cards is no longer sufficient.

Difference between RAM and ROM

ROM stands for read only memory. Unlike RAM, ROM is used to record information that will be stored there permanently. For example, ROM is used in the following devices:

• Cell phones;
• Smartphones;
• Microcontrollers;
• BIOS ROM;
• Various consumer electronic devices.

In all the devices described above, the code for their operation is stored in ROM. ROM is non-volatile memory, therefore, after turning off these devices, all information will be stored in it - which means this is the main difference between ROM and RAM.

Let's sum it up

In this article, we briefly learned all the details, both in theory and in practice, regarding random access memory and their classifications, and also looked at the difference between RAM and ROM.

Also, our material will be especially useful to those PC users who want to find out their type of RAM installed in the computer, or find out which RAM must be applied to different configurations.

We hope our material will be interesting for our readers and will allow them to solve many problems related to RAM.

Video on the topic

Now we will try to find out what RAM (random access memory) is, and also consider the main types of modern, and not so modern, computer RAM.

Random Access Memory (RAM) - part of a computer system that temporarily stores data and instructions necessary for the processor to perform various operations. Data is transferred to RAM by the processor directly or through ultra-fast memory. To put it simply, these are the elements of the “stuffing” of the system unit, which serve to store programs launched by the user, and to provide the processor with quick access to them. Now let's move directly to memory types. PC RAM can be divided into two types: SRAM (static type) and DRAM (dynamic type). Read more about each of them below:

(Dynamic Random Access Memory) - dynamic memory type, these are the same rectangular RAM strips that we insert into slots on the motherboard. To store a bit or trit, a circuit consisting of one capacitor and one transistor (in some variations there are two capacitors) is used. This type of memory solves, firstly, the problem of high cost (one capacitor and one transistor are cheaper than several transistors) and, secondly, compactness (where SRAM houses one trigger, that is, one bit, eight capacitors and transistors can fit), this type of memory has a number of disadvantages:

• such memory works slower than SRAM type memory, which means the access time to the information it contains increases;
• the second disadvantage is the discharge of the capacitors that make up the DRAM: in order not to lose the contents of the memory, the charge of the capacitors must be “regenerated” after a certain time interval. Regeneration is performed by a central microprocessor or memory controller. Since all memory operations are periodically suspended to regenerate memory, the performance of this type of RAM is significantly reduced.

SRAM (Static Random Access Memory) – a static type of memory, which is usually based on flip-flops, this type of RAM does not need regeneration and the advantage of this type of memory is speed. Since the triggers are assembled on gates, and the gate delay time is very short, switching the trigger state occurs very quickly, but the disadvantage of this type of memory is its high cost. Also, the group of transistors included in the trigger takes up much more space than capacitors, so the volume of such memory is limited. This type of memory is used to organize ultra-fast memory ( memory cache), the cache in turn is used in processors, hard drives, and in other devices.

The most important characteristic on which memory performance depends is its bandwidth. Modern memory has a bus width of 64 bits (or 8 bytes), so the bandwidth of DDR800 memory is 800 MHz x 8 Bytes = 6400 MB per second. Hence, another designation for memory of this type follows – PC6400. Recently, two-channel and three-channel memory connections are often used, in which its bandwidth is doubled and tripled accordingly. Thus, in the case of two DDR800 modules, we will get the maximum possible data transfer speed of 6.4 GB/s and 12.8 GB/s, but this is just in theory; in practice, things are different and the increase from such modes is quite insignificant.

Now let's talk in more detail about the types of dynamic RAM:

DDR- used in very old systems and, due to its antiquity, has a number of shortcomings in the structure of the modules and has a low data transfer rate.

DDR2– this type of memory is gradually losing relevance these days, but is still used by many computers. The data transfer speed of DDR2 is an order of magnitude higher than that of DDR (the slowest DDR2 model is equal in speed to the fastest DDR model).

DDR3- the most common type of memory today. If we take into account the data transfer speed, it is again higher than that of the previous generation memory (The slowest DDR3 model is equal in data transfer speed to the fastest DDR2 model).

DDR4- a new type of RAM, differing from previous generations by higher frequency characteristics and low voltage. Will support frequencies from 2133 to 4266 MHz.

Table 1: Technical characteristics of RAM according to JEDEC standards

Maximum memory performance is also affected by such important parameters as “memory timings”.

Timing- this is the delay between individual operations performed by the controller when accessing memory. If we consider the composition of the memory, we get: its entire space is presented in the form of cells (rectangles), which consist of a certain number of rows and columns. One such "rectangle" is called a page, and the collection of pages is called a bank. To access a cell, the controller sets the bank number, the page number in it, the row number and the column number, time is spent on all requests, in addition, quite a large cost is spent on opening and closing the bank after the read/write operation itself. Every action takes time, it is called timing.

Tyumen State Oil and Gas University

Department of Automation and Control

Guidelines for laboratory work No. 1.4

"RAM"

Tyumen 2005

Goal of the work : Study of types of RAM.

RAM: basic concepts

RAM This is the work area for the computer's processor. It stores programs and data during operation. RAM is often thought of as temporary storage because data and programs are only stored in it when the computer is turned on or until the reset button is pressed. Before turning off or pressing the reset button, any data changed during operation must be saved to a storage device that can store the information permanently (usually a hard drive). When the power is turned on again, the saved information can be loaded into memory again.

Random access memory devices are sometimes called random access storage devices. This means that access to data stored in RAM does not depend on the order in which it is located in it. When people talk about computer memory, they usually mean random access memory, primarily the memory chips or modules that store active programs and data used by the processor. However, sometimes the term memory also applies to external storage devices such as disks and tape drives.

Over the course of several years, the definition of RAM (Random Access Memory) has evolved from a common abbreviation to a term denoting the main working memory space created by Dynamic RAM (DRAM) chips and used by the processor to execute programs. One of the properties of DRAM chips (and, therefore, RAM in general) is dynamic data storage, which means, firstly, the ability to repeatedly write information to RAM, and secondly, the need to constantly update data (i.e., essentially rewriting them) approximately every 15 ms. There is also the so-called static RAM (SRAM), which does not require constant data updating. It should be noted that data is saved in RAM only when the power is turned on.

Term RAM often refers not only to the chips that make up the memory devices in a system, but also includes concepts such as logical mapping and layout. Logical mapping is a way of representing memory addresses on the actual installed chips. Placement is the location of information (data and commands) of a certain type at specific system memory addresses.

While a program is running, its data is stored in RAM. Random access memory (RAM) chips are sometimes called volatile memory: if the computer is turned off, the data stored in them will be lost unless it was first saved to a disk or other external memory device. To avoid this, some applications automatically backup your data.

The files of a computer program, when it starts, are loaded into RAM, in which they are stored while working with the specified program. The processor executes software-implemented instructions contained in memory and stores their results.

RAM stores the codes of the keys pressed when working with a text editor, as well as the values ​​of mathematical operations. When you execute the Save command, the contents of RAM are saved as a file on your hard drive.

Physically, RAM in a system is a set of chips or modules containing chips that are usually connected to the motherboard. These chips or modules can have different characteristics and, in order to function correctly, must be compatible with the system in which they are installed.

Modern computers use three main types of storage devices.

ROM (Read Only Memory). Read-only memory is ROM that is not capable of writing data.

DRAM (Dynamic Random Access Memory). Dynamic random access memory.

SRAM(Static RAM). Static RAM.