The concept of "computer memory" is very vague. It may include information storage devices or storage devices. Therefore, the characteristic of memory depends on what is at stake.
Computer memory is an element of a computer, a physical device, or a medium for archiving information. Used for calculations taking place in a specific period.
Briefly about the system memory
They started talking about the characteristics of memory back in 1940. Then this element of the PC became important as well as the central processor. Since then, memory is represented by a hierarchical structure, it can use several devices at once to record data, each of which has its own characteristics and functions.
There are several types of memory in a personal computer . Most often they think of a dynamic storage device - RAM. Although it should also include a hard drive, disks, flash drives and previously used diskettes.
Storage Tasks
To determine the characteristics of memory, you need to understand its task. This part of the PC saves the state of the system and information in its cells. "Electronic cells" can remember the physical impact. To access such information, you need to use a special mechanism.
The access process itself is a phased process. Processes are time dependent and are divided into write and read operations. These controllers are controlled by memory controllers. There is also an erase operation that fills the cells with the same values.
Storage Features
Of course, the main function of memory is the long-term storage of data. Together with the CPU, it is part of von Neumann architecture, on which the entire system of modern computers is built.
The first models used memory as an archive for the processed information. They were developed according to a special program, which required hard execution of sequential processes. With the advent of von Neumann architecture, everything has changed.
All stored data has been converted to bits. Therefore, dependence on the physical principle, calculus and other factors has disappeared. Now any data: text, image, video, etc. - can be represented by a sequence of bit strings. Thus, it became possible to “compress” text files, placing them in 1 MB.
Since engineers have not yet developed a universal device that could perform many tasks at once, it is necessary to install several storage systems in modern PCs at once.
Types of Computer Memory
To go to the technical characteristics of memory, you need to consider its types.
It should be noted right away that there are two types of classifications: one describes the memory functionality, the second its technical implementation.
Since we are talking about the characteristics of recording systems, we will consider precisely the classification of storage devices.
The main groups:
- form of recorded information;
- the ability to record;
- the ability to overwrite;
- appointment;
- volatility;
- type of access.
These are the main groups that describe PC memory in terms of technical implementation.
Recorded Information
All recording systems can be divided into analog and digital. In the first case, the signal is represented by parameters that are described by a function of time and have a continuous set of possible values.
Digital are intended for record, storage and reading of data which are transformed to a digital code. The characteristics of this type of memory are:
- information capacity;
- power consumption;
- data storage time;
- speed of work.
Recording ability
This group of storage devices, as the name implies, is characterized by the ability to record. So, there are systems on which data can be written:
- manufacturer only;
- user with special mechanism;
- end user with the same device that uses memory.
The last type includes all existing data storage devices in the PC.
Rewritable
A similar group that contains three subgroups:
- write-once devices;
- reprogrammable mechanisms that can make and change data several times, but at the same time have either a limited number of write cycles, or write information more and more slowly each time;
- multiple recording devices.
The last subgroup is represented by hard drives or flash drives.
Appointment
The next group has its own technical characteristics:
- random access memory stores data of system processes;
- internal - represented by devices that can store data for a long time;
- external - it can also store data for a long time, but most often serves as a backup archive or information carrier;
- there are devices that identify or make payments.
Volatility
One of the key characteristics of PC memory. Devices may or may not depend on energy. In the first case, all data disappears after a power outage. In the second - the information remains on the keeper.
Volatile devices can be static or dynamic. In the first case, to save data, it is enough to maintain the power of the mechanism, in the second case, information is destroyed over time and in addition to maintaining power, it is necessary to regenerate.
Access
This point also plays an important role in characterizing PC memory. There are several access options. For example, magnetic tapes work with sequential reads, and random access memory works with random reads.
Hard drives provide direct access, and database devices provide associative access.
Basic PC elements
Since it makes no sense to talk about all the variations of memory, consider the one that is used in a modern user computer.
Assembling a system or buying a ready-made one, you can find a motherboard inside the chassis. It usually houses all the main parts of the PC. There is a central processor, without which it is difficult to imagine the operation of the system, maybe a video card, although it is also an optional element.
On the motherboard there is RAM - the computer's RAM, the characteristics of which will be described below. You can also connect external memory to a PC. It can be represented by a solid state or hard disk, an optical device or flash memory. All these elements are supported by the power supply.
Inner memory
Another element of the system that is worth mentioning. The fact is that many people think that internal memory is a hard drive. This is actually not the case.
Internal memory is organized by cells on the motherboard. It can be fast volatile and constant. The first group includes RAM, and with it the cache of two levels. The constant include ROM and CMOS RAM.
ROM or ROM is a non-volatile memory that stores immutable data. To make it easier to understand: it conditionally contains a set of rules and algorithms according to which the system can function correctly. The mouse moves in the indicated direction, the "Start" opens on demand, etc.
CMOS RAM did not appear immediately. Previously, only the ROM BIOS was used. But she decided to complement this non-volatile operating system. It collects information about the time and date, alarm clock and various PC configurations.
Cache is called super-operative memory. This PC memory has few characteristics. It has a very small volume and works only in conjunction with a microprocessor and RAM. The main task: to accelerate the overall time and speed of data processing.
RAM
Since this is one of the main elements of the system, we need to dwell on this issue. RAM is a volatile device in the system that stores machine code and intermediate data that the processor works with. RAM works when the PC is turned on. The exchange of memory occurs directly or through the cache.
Since this is a volatile device, the data on it is available only when voltage is applied. If the RAM power is cut off, even for a split second, then the information may be destroyed or distorted.
With the development of technology, it became possible to turn on the energy-saving mode. In this case, the main characteristics of the RAM go to "Sleep". If the PC is transferred to hibernation, the RAM power will turn off, but before that, the memory will transfer the stored data to the ROM in the hiberfil.sys file. When the system resumes, this file releases data “at will”.
RAM in modern systems
If you have ever seen the design of a PC inside the chassis, you know that the RAM is represented by dynamic memory modules on which semiconductors are located.
Distinguish between dynamic and static type. The first is cheaper, but slower. Its density is higher, so more memory cells are placed on one crystal. Hence the reduced speed.
But static memory is very fast, but expensive. At the moment, it is disadvantageous to use it in RAM modules, therefore it is located in the cache memory and microprocessor design.
The main characteristics of RAM
This volatile device has a lot of parameters. That is why when buying modules there are problems with the choice. But if you understand at least the basic parameters, the picture becomes clearer.
The average user should know about:
- type;
- volume;
- frequency
- manufacturer.
RAM Type
The characteristics of RAM include the type of RAM - this is one of the main parameters that are paid attention to. If you lose with it, then the module may not stand on the motherboard. During the existence of the "RAM", its types have been actively changing.
More recently, the most popular was DDR3. Now this type is on sale the cheapest. But many advanced users prefer DDR4. This is due to its improved performance, and less voltage and energy consumption.
In 2020, they plan to introduce DDR5 into a market that will become twice as fast and energy efficient as its predecessor. It is assumed that the density will increase, and accordingly the volume.
RAM size
Of course, the characteristics of 2 GB of RAM differ from the same 4 GB module only in volume. Otherwise, there may not be any differences if they are models of the same manufacturer.
The volume is always of most interest to the user, since the performance and operability of the system depend on this. This has become especially relevant with the release of labor-intensive games that can be disabled due to a lack of "RAM".
If the PC is working, then enough RAM for 4 GB. Characteristics of gaming systems are more demanding. In this case, it is better to get 16 GB of RAM.
RAM frequency
Another parameter that you should pay attention to when buying RAM. With each new series, the frequency increases, which affects the throughput.
But do not think that when installing high-frequency memory, performance will noticeably increase. In addition, not every system can reveal the potential of the RAM module.
RAM manufacturer
This is not the main characteristic of RAM, but sometimes it is very important when buying RAM. Some manufacturers provide quality but expensive products. There are those that have distinguished themselves by producing different series for a desktop, gaming PC or server station. The most popular now are: Kingston, HyperX, Corsair and Samsung.
Characteristics of laptop RAM
The RAM parameters for the laptop practically do not differ from the full-size versions. A low-sided, dual-sided SO-DIMM is used. This is a single format for all laptops. It has been specifically designed for systems with limited space.
In addition, you will have to pay attention to the volume. Now the optimal module for work is 4 GB. The memory type is better to choose DDR4, because it is already improved and so far the best among the rest.
External memory: disk
Many types belong to this type of memory, but it makes no sense to consider everything, because part is no longer used - for example, floppy disks. Even optical discs are no longer in use. Therefore, we will consider the characteristics of the computer's external memory for hard (HDD) and solid-state (SSD) drives.
Separately consider the parameters of each device does not make sense, since they are almost the same. The only SSD is a more advanced version of the HDD.
Among the main characteristics of memory devices of this type, several parameters are distinguished. SATA interface is used in both drives. Capacity is a parameter that can reach 10 GB. Although in the case of SSD this does not happen, since the device is very expensive in itself, and such a volume will not be in demand. But for the 10 GB HDD, although unusual, it’s real.
Physical size is a characteristic that is also called a form factor. The railway has a size of 3.5 inches, the SSD - 2.5. Also, the characteristics can include energy consumption indicators. For SSDs, they will always be lower. But the number of input operations and conclusions on the contrary, the SSD is higher.
External memory: flash drives
We can not but mention flash drives. They also relate to computer memory and have technical specifications. Their task and parameters:
- save information;
- transfer data from a PC to devices;
- work with independent power and have low power consumption;
- non-volatile;
- high speed;
- compact.
Flash drives can take the form of a small card, which is placed in cameras, camcorders, navigators, smartphones and tablets, recorders and other devices.
Among their characteristics, it is worth highlighting the format, volume and speed of data recording. Each device requires its own type of flash drive, so you should carefully study this issue when choosing.
There are also external drives - USB sticks. They differ from the "cards" in that they have more volume, size, speed and consumption. There are also different variations of the standards, although USB A is still the most popular.
A lot of time has passed since the creation of such a drive. USB versions have also changed: 1.1, 2.0 and 3.0. The latter is only being implemented on the panel of motherboards and PCs, but is the fastest. It has a blue color so that it is not confused with previously released formats. But if you connect it to the USB 2.0 connector, then it adapts to it.
findings
The main characteristics of computer memory are difficult to generalize, since the devices in the system are very different. Apparently, therefore, they have not yet developed a universal mechanism that would combine RAM, ROM, SSD, and even flash memory.
On the other hand, it would not be very convenient for the user. Therefore, each device has its own characteristics, which are affected by the manufacturer, cost, popularity and other factors.
So, RAM has a volume, frequency, voltage and type. Similar characteristics and external drives (HDD and SSD). The buyer looks at the form factor, interfaces, volume and overall performance. Even a flash drive has similar parameters, among which there is again the volume, format, speed.
Despite this similarity in technical specifications, these devices are responsible for their specific tasks. RAM stores temporary process information on a PC. But the hard and solid state drive saves the personal information of the user and the system. A flash drive also saves any data, but it can be a “carrier” of them to other devices.