Defragmentation of the ssd disk is necessary. Everything you need to know about defragmenting your hard drive. What is an SSD drive
Code - a system of conventional signs (symbols) for transmitting, processing and storing information (messages).
Coding- the process of presenting information (messages) in the form of code.
The entire set of symbols used for encoding is called alphabet coding. For example, in computer memory, any information is encoded using a binary alphabet containing only two characters: 0 and 1.
The scientific foundations of coding were described by K. Shannon, who studied the processes of transmitting information through technical communication channels ( communication theory, coding theory). With this approach coding understood in a narrower sense: how transition from representation of information in one symbolic system to representation in another symbolic system. For example, converting written Russian text into Morse code for transmission via telegraph or radio communications. Such coding is associated with the need to adapt the code to the technical means of working with information used (see “ Transfer of information”).
Decoding - the process of converting code back to the form of the original symbol system, i.e. receiving the original message. For example: translation from Morse code into written text in Russian.
In a broader sense, decoding is the process of reconstructing the content of an encoded message. With this approach, the process of writing text using the Russian alphabet can be considered as encoding, and reading it is decoding.
Coding goals and coding methods
The way to encode the same message may be different. For example, we are used to writing Russian text using the Russian alphabet. But the same can be done using the English alphabet. Sometimes you have to do this by sending an SMS on a mobile phone that does not have Russian letters, or sending an email in Russian from abroad if the computer does not have Russified software. For example, the phrase: “Hello, dear Sasha!” you have to write like this: “Zdravstvui, dorogoi Sasha!”
There are other ways to encode speech. For example, shorthand - a quick way to record spoken language. It is used only by a few specially trained people - stenographers. The stenographer manages to record the text synchronously with the speech of the speaker. In the transcript, one icon represented an entire word or phrase. Only a stenographer can transcribe (decode) the transcript.
The above examples illustrate the following important rule: different methods can be used to encode the same information; their choice depends on a number of circumstances: coding goals, conditions, available funds. If you need to write down the text at the pace of speech, we use shorthand; if you need to send text abroad, we use the English alphabet; If you need to present the text in a form understandable to a literate Russian person, we write it according to the rules of Russian grammar.
Another important circumstance: the choice of how information is encoded may be related to the intended method of processing it. Let's show this using the example of representing numbers - quantitative information. Using the Russian alphabet, you can write the number “thirty-five”. Using the alphabet of the Arabic decimal number system, we write: “35”. The second method is not only shorter than the first, but also more convenient for performing calculations. Which notation is more convenient for performing calculations: “thirty-five times one hundred and twenty-seven” or “35 x 127”? Obviously the second one.
However, if it is important to preserve the number without distortion, then it is better to write it in text form. For example, in monetary documents the amount is often written down in text form: “three hundred seventy-five rubles.” instead of “375 rub.”. In the second case, distorting one digit will change the entire value. When using text form, even grammatical errors may not change the meaning. For example, an illiterate person wrote: “Three hundred and seventy-five rubles.” However, the meaning remains.
In some cases, there is a need to classify the text of a message or document so that those who are not supposed to read it cannot. It is called protection against unauthorized access. In this case, the secret text is encrypted. In ancient times, encryption was called secret writing. Encryption is the process of converting plaintext into ciphertext, and decryption- a reverse conversion process in which the original text is restored. Encryption is also encoding, but with a secret method known only to the source and recipient. Encryption methods are the subject of a science called cryptography(cm . "Cryptography").
History of technical methods of encoding information
With the advent of technical means of storing and transmitting information, new ideas and coding techniques arose. The first technical means of transmitting information over a distance was the telegraph, invented in 1837 by the American Samuel Morse. A telegraph message is a sequence of electrical signals transmitted from one telegraph apparatus through wires to another telegraph apparatus. These technical circumstances led S. Morse to the idea of using only two types of signals - short and long - to encode messages transmitted over telegraph communication lines.
Samuel Finley Breese Morse (1791–1872), USA
This coding method is called Morse code. In it, each letter of the alphabet is encoded by a sequence of short signals (dots) and long signals (dash). Letters are separated from each other by pauses - the absence of signals.
The most famous telegraph message is the SOS distress signal ( S ave O ur S ouls- save our souls). Here's what it looks like in Morse code applied to the English alphabet:
–––
Three dots (letter S), three dashes (letter O), three dots (letter S). Two pauses separate the letters from each other.
The figure shows Morse code in relation to the Russian alphabet. There were no special punctuation marks. They were written with the words: “tchk” - period, “zpt” - comma, etc.
A characteristic feature of Morse code is variable code length of different letters, that's why Morse code is called uneven code. Letters that appear more often in the text have a shorter code than rare letters. For example, the code for the letter “E” is one dot, and the code for a solid character consists of six characters. This is done in order to reduce the length of the entire message. But due to the variable length of the letter code, the problem of separating letters from each other in the text arises. Therefore, it is necessary to use a pause (skip) for separation. Consequently, the Morse telegraph alphabet is ternary, because it uses three characters: dot, dash, space.
Uniform telegraph code was invented by the Frenchman Jean Maurice Baudot at the end of the 19th century. It used only two different types of signals. It doesn’t matter what you call them: dot and dash, plus and minus, zero and one. These are two different electrical signals. The code length of all symbols is the same and equals five. In this case, there is no problem of separating letters from each other: each five signals is a text character. Therefore, a pass is not needed.
Jean Maurice Emile Baudot (1845–1903), France
The Baudot code is the first method of binary coding of information in the history of technology.. Thanks to this idea, it was possible to create a direct-printing telegraph apparatus that looked like a typewriter. Pressing a key with a certain letter generates a corresponding five-pulse signal, which is transmitted over the communication line. The receiving device, under the influence of this signal, prints the same letter on a paper tape.
Modern computers also use uniform binary code to encode texts (see “ Text coding systems”).
The topic of information coding can be presented in the curriculum at all stages of studying computer science at school.
In a propaedeutic course, students are more often offered tasks that are not related to computer data coding and are, in a sense, in the form of a game. For example, based on a Morse code table, you can propose both encoding tasks (to encode a Russian text using Morse code) and decoding tasks (to decipher a text encoded using Morse code).
The execution of such tasks can be interpreted as the work of a cryptographer, offering various simple encryption keys. For example, alphanumeric, replacing each letter with its serial number in the alphabet. In addition, to fully encode text, punctuation marks and other symbols should be added to the alphabet. Have students come up with a way to differentiate lowercase letters from uppercase letters.
When performing such tasks, you should draw the students' attention to the fact that a separating character is required - a space, since the code turns out to be uneven: some letters are encrypted with one number, some with two.
Encourage students to think about ways to avoid separating letters in the code. These thoughts should lead to the idea of a uniform code, in which each character is encoded with two decimal digits: A - 01, B - 02, etc.
Collections of problems on coding and encrypting information are available in a number of textbooks for school.
In a basic computer science course for primary school, the topic of coding is more closely associated with the topic of representing various types of data in a computer: numbers, texts, images, sound (see “ Information Technology”).
In high school, the content of a general education or elective course may cover in more detail issues related to the coding theory developed by K. Shannon within the framework of information theory. There are a number of interesting problems here, the understanding of which requires an increased level of mathematical and programming training of students. These are problems of economical coding, universal coding algorithm, and error-correcting coding. Many of these issues are covered in detail in the textbook “Mathematical Foundations of Computer Science”.
1. Andreeva E.IN.,Bosova L.L.,Falina I.N. Mathematical foundations of computer science. Elective course. M.: BINOM. Laboratory of Knowledge, 2005.
2. Beshenkov S.A.,Rakitina E.A. Computer science. Systematic course. Textbook for 10th grade. M.: Laboratory of Basic Knowledge, 2001, 57 p.
3.Wiener N. Cybernetics, or Control and Communication in Animals and Machines. M.: Soviet radio, 1968, 201 p.
4. Computer science. Problem book-workshop in 2 volumes / Ed. I.G. Semakina, E.K. Henner. T. 1. M.: BINOM. Laboratory of Knowledge, 2005.
5. Kuznetsov A.A., Beshenkov S.A., Rakitina E.A., Matveeva N.V., Milokhina L.V. Continuous course in computer science (concept, system of modules, standard program). Informatics and Education, No. 1, 2005.
6. Mathematical encyclopedic dictionary. Section: “Dictionary of school computer science.” M.: Soviet Encyclopedia, 1988.
7.Friedland A.I. Computer science: processes, systems, resources. M.: BINOM. Laboratory of Knowledge, 2003.
You must clearly understand: this device is fundamentally different from the usual HDD drive. And in order for the SSD to last as long as possible, try to avoid the same things that you did with a regular hard drive. Let's take a closer look at what to avoid.
If in the FAT32 file system disk defragmentation was still necessary, then with the transition to NTFS this process is no longer necessary. And you shouldn’t even think about defragmenting an SSD drive.
The fact is that solid-state drives have a limited read-write cycle, and therefore overwriting the contents will not increase their service life in any way. Of course, modern SSDs have quite a sufficient number of cycles, which is unlikely to be exceeded by defragmentation. The reason is simple: for a solid-state drive, the defragmentation procedure in the classical sense is meaningless.
The hard drive has mechanical components (the head) that physically move along the disk. Therefore, if information is scattered across the disk, the head will have to make a large number of physical movements. There are no moving parts in an SSD: access to any location is equally fast.
Do not use an OS younger than Windows 7
When installing a modern drive, make sure that your computer has a modern operating system installed. Windows Vista and earlier versions do not support the TRIM feature, which completely erases information from the disk. This command instructs the SSD that the files have been deleted and the space previously occupied by them should be cleaned up.
In the case of using older OS, after deletion, the data physically remains on the disk, and there is a possibility of it being . In addition, using an SSD in a system without support for the TRIM function slows down the computer: the OS first erases the existing information before writing data, which leads to a decrease in read-write speed.
Do not write data to the SSD "to capacity"
As strange as it may sound, for a solid-state drive to fully operate, it is necessary that it be filled with information to no more than 75% of its volume. The thing is that when there is little free space left on the SSD, cells partially filled with data appear. When writing data, information from these cells is first dumped into the cache and then written again.
In other words, writing data to an empty cell is very fast, but writing data to a partially filled cell is slow, due to the need to perform auxiliary operations. It has been experimentally established that for optimal performance the SSD should be kept no more than 75% full.
Use your SSD correctly
Storing multimedia files on a solid-state drive is not a good idea. To watch movies and listen to music in the highest quality, the speed of a regular hard drive is quite enough. The SSD should store the operating system, as well as data that needs quick access: programs, games, etc. And if space does not allow, then for a home multimedia library you should purchase an external hard drive with a USB 3.0 interface, this will be more than enough.
Perhaps the most important disadvantage is their limited service life.
Essentially, an SSD drive is a set of flash memory cells and each such cell has its own resource. Today, drives with a resource of 100,000 rewrite cycles have already appeared and technology does not stand still, but still the resource of SSD drives is limited.
In this post, I would like to reflect on the topic of solid-state drives, since this process involves moving pieces of information from one part of the disk to another, and therefore it is logical to assume that defragmentation wears out the SSD drive, reducing its lifespan.
So is defragmentation of SSD drives necessary? Let's figure it out.
So, modern operating systems and programs are not very ready to work with SSD drives. If we analyze the work of the same Windows, we will find out that the operating system creates hundreds and thousands of temporary files during its operation. For example, designed to compensate for the lack of RAM, it is constantly increasing or decreasing, and is cleared when exiting the operating system. Browsers (programs for viewing Internet pages) are constantly connected to the Internet, which allows you to quickly access regularly visited Internet resources, but again loads the SSD drive. There are many such examples. Even the well-known Word, when creating a text document, performs autosaving, which already means an additional rewriting cycle on the information storage device.
All these seemingly one-time actions result in tens of thousands of rewrite cycles annually, which, as you understand, directly affects the resource of the SSD drive.
To ensure that the wear of the cells of an SSD device is uniform, device manufacturers embed a special program into it, which, according to a certain algorithm, distributes cells for writing or rewriting information. The task of this program is to make the wear of the cells uniform, that is, in each cell of the drive the number of rewrite cycles should be approximately the same. The idea is not bad, but it does not work 100%. If we look at the operating system or program files that we have installed on a solid-state drive, we will find tens of gigabytes of files that cannot be overwritten. After all, the main files of the operating system or programs do not change over time, and their volume is significant. The same can be said about your personal information. Once you have dropped your photo archive, favorite movies or music, you are unlikely to work with these files in any way and they will remain in the same cells of the SSD drive for a very long time.
As a result, it turns out that there is a certain space of cells on the drive that are constantly being overwritten, and there are permanent cells that do not work at all. This leads to the logical conclusion that the program built into the SSD drive and designed to increase its service life is ineffective.
Now about the essence, that is, about the topic stated in the title of the note.
On the one hand, defragmentation on SSD drives is redundant, since solid-state drives have a completely different operating principle than hard drives and fragmentation of files on an SSD drive does not affect its operating speed.
In this regard, in the Windows 7 operating system, scheduled defragmentation is even specially disabled so as not to additionally load the SSD device, but is defragmentation so harmful? Or is it still necessary?
Perhaps in the form in which it exists now, defragmentation will not help much and will not help increase the resource of the SSD drive, since during defragmentation, fragments of files that were written to an already fragmented disk are shuffled. But still, one-time defragmentation will allow you to partially move file fragments and free up cells in which these fragments are stored for a long time. In the future, defragmentation will only use areas of the SSD drive in which cells are constantly being overwritten, that is, those areas in which temporary files are saved, which will only lead to greater wear and tear on the cells.
I am sure that defragmenter programs (or some other name) will soon appear that will move files on an SSD drive to wear out all its cells evenly. In the meantime, owners of laptops with SSD drives will have to come to terms with the fact that some of its cells will fail much faster than the resource of others is exhausted.
If you have an SSD installed on your computer, then you should disable the automatic defragmentation process, if one is running, and forget about this procedure altogether.
Many users are wondering how exactly Windows SSD defragmentation should be done, and is it necessary? After all, with the release of the new generation of solid-state drives, it was stated that they would make a person’s life much easier and relieve him of such routine work as organizing data on an SSD. However, many users simply did not believe this statement. This is understandable, because an SSD is a regular hard drive, which, like any other device in a computer, requires careful care. Moreover, today there is not as much information about SSDs as we would like. So what is defragmentation and what happens when it does it? Is it a vital necessity or is it a completely useless measure?
What is an SSD drive?
In order to correctly answer the above question, you need to understand what Windows 7 SSD drives are. These are the same hard drives, only made according to a completely different principle. SSD Windows uses completely new technologies in its structure, which, naturally, carry quite a lot of potential.
Advantages of an SSD drive
So, in Windows 7, these types of devices provide better data transfer within the system itself than other solid-state drives. This factor is achieved due to the original structure of the disk and the Windows 7 system, which allows you to move even large files within the drive in a few seconds. That is why these types of elements are actively used in Windows 7 by those users who like high transfer speeds.
In addition to all of the above, elements of this plan for Windows 7 provide faster access to 
files and folders from the software side. For example, the same Windows 7 works much faster and more efficiently if it is on an SSD, and not on any other hard drive. This is achieved due, again, to new technology and the excellent interaction of Windows 7 with this type of device. It should be noted that gamers who want to play games for Windows 7 also like to purchase such discs. After all, the frame rate in gaming products depends not only on the power of the processor and motherboard, but also on the spindle speed of the Windows 7 hard drive. But, As you know, a lot of games have been released for Windows 7.
We should summarize and once again go through the main advantages of an SSD drive:
- High speed of file transfer within the system. So, if a hard drive of this type has two partitions, then moving even large files between them is carried out almost instantly.
- Fast software access to necessary files and folders. Thanks to the latest technologies in this area, access to various types of information from any program has become truly impressive.
Disadvantages of an SSD drive
Like any other device, a hard drive of this type also has its drawbacks, which should definitely be mentioned. They are:
- limited memory capacity;
- short service life;
- high price.
Indeed, this disc does not have as many disadvantages as it seems at first glance. They are still quite significant for such a disc.
Limited disk space refers to the amount of storage space available in the market today. Of course, this part of the disk is really small even for the average user. For example, a disk capacity of 128 GB, which is affordable for the majority of the population, is only useful for installing the system and several demanding games. If we take larger disk volumes, then we cannot do without a capital investment of funds, which not everyone has, especially for such a luxury.
Another disadvantage of this disk is its rather limited service life. This is influenced by one, but the most important factor, for which the resources of this disk are not prepared - this is the constant overwriting of the data stored on the disk. As you know, when working with any files, the operating system creates temporary elements that contain information about all current processes. After work with any object is completed, all its temporary files are destroyed, and after Windows shuts down, all temporary files are completely erased. Over the course of a year of PC operation, there will be at least several thousand such rewrite cycles, which, of course, negatively affects the performance of some areas of the disk.
Well, another disadvantage is the relatively high cost of such a device. In order to purchase it, you need a really large amount, because this new product is not yet very widespread, especially in our country.
Defragmentation: necessary or not?
The most important question that all users ask when buying such a hard drive is. I would like to note right away that for this type of disk it is best to completely disable automatic defragmentation of the operating system, which will only interfere. Of course, you should disable any other similar process, so as not to waste the purchased item.
Judging by the advertising of such disks, there is no need to defragment SSDs at all, since the disk itself already has a built-in program for distributing data over the entire disk area. However, if it were possible to disable this built-in function, it would be worth using it. It would seem, how can you disable something that the developers themselves implemented into their invention? After all, they probably know better than the users what is good and what is not. But in reality, everything turns out to be completely the opposite and disabling this program, if possible, would not hurt.
The thing is that you should disable defragmentation of such a disk because it leads to gradual wear and tear of the device. In turn, the built-in program copes with this function perfectly. This is partly true, but the problem lies elsewhere. After all, as you know, there are files that the user works with constantly and they change from time to time. Accordingly, the standard SSD disk utility identifies them and frees free cells, organizing these files. But there are other objects with which the user does not perform any manipulations at all. As a rule, such data are considered to be collections of music and films that remain unchanged over time. Naturally, the standard program does not defragment them, since they always occupy the same cells. But, as practice shows, defragmentation is also necessary for such files, because they also take up some space. So, if you look at it from a completely different angle, then defragmentation is even necessary for such disks. But it is still not recommended to defragment them.
So why is defragmenting this kind of disk harmful? The answer to this question lies in the same program that organizes frequently used files. After all, if you defragment a disk with a third-party utility, it will also organize frequently used data. But the standard program also performs this same function. Therefore, it is not difficult to guess that such a double measure will very quickly render the disk unusable.
It makes sense to use defragmentation only once, after all important files have been transferred to disk and a single and main collection of files has been formed. After all, third-party defragmentation programs can not only organize frequently used data, but also distribute those parts of files that have been stored for quite a long time.
To summarize, I would like to note that technology does not stand still and, perhaps, very soon special tools will be invented that will effectively defragment new SSD drives. However, for now, it is best to avoid regularly defragmenting this resource, which is immune to this process. Still, if you look at it this way, a standard file organizing program can do a good job of its main function - distributing parts of frequently used files. If we talk about all other methods, then they are not at all effective elements that are best ignored at other times. And for that matter, with proper care and careful software handling, this kind of disk will serve the average user no less than solid-state drives of the previous generation.
Quite a long time has passed since the appearance of solid state drives (Solid State Drive - SSD) on the market. Prices for this product are gradually decreasing, making it more and more affordable, and now a 120 GB drive will cost about 4 thousand rubles. In fact, if you want to upgrade your PC now, then buying an SSD will be one of the most cost-effective options. You don’t have to throw away your existing hard drive (it will only partially change its function, becoming a storage for media and other heavy files), and the computer’s performance in almost all operating modes will increase noticeably.
Users who are not particularly interested in the world of hardware may not clearly understand the fundamental difference between an SSD and the usual magnetic hard drive HDD, and they often see the new product as the same HDD, only faster, smaller, lighter and more expensive. It is precisely the lack of understanding of the fundamental differences in the operation of HDD and SSD that can lead to incorrect use of SSD, which in especially severe cases will reduce all its advantages to zero. Yes, the solid-state drive needs to be used correctly, but do not be afraid - the user does not require any painstaking daily deeply technical actions. Rather, it's simply required to not do a few simple things, and today we're presenting a list of "don'ts" for anyone considering powering up their workhorse with a fast SSD.
For the techies who have discerned captaincy here, we ask you to take into account the fact that if you know all this, then you probably also know the fact that there are other people who may not know all this. Replace the usual “thank you cap” with your additional advice, together we will make the Internet more useful.
Don't defragment
There is no need to defragment the SSD. If in the old Windows with FAT32 you defragmented by inertia (although NTFS works fine without it), then with the purchase of an SSD you can and should forget about defragmentation (the SSD itself) altogether.
SSDs have a limited number of write cycles (as a rule, the cheaper the disk, the less resource it has), and such shoveling of its contents will definitely not benefit the lifespan. Yes, recent SSD models have a very large supply of write cycles, and you are unlikely to reach the limit when the disk stops working correctly, even with frequent recording, but the point here is rather that defragmentation itself is pointless for SSDs.
HDDs use mechanical parts. The head that reads the data wanders back and forth across the surface of the magnetic disk. Accordingly, the more specific data is scattered across the disk, the more movements and time it needs to completely read this data. Nothing moves in an SSD, and access to any memory cell is equally fast and does not depend in any way on the relative position of this data.
Don't format
We are accustomed to the fact that in order to completely and permanently delete data from the HDD, it is necessary to use additional tools: formatting, special utilities like DBAN or the Wiper tool included in CCleaner. This is done so that a cunning attacker will not be able to recover the data you deleted from the disk using a utility like Recuva.
In the case of SSDs, everything is different. The point here is not even in the drive itself, but in the operating system. If you are using a more or less current OS (Windows 7+, Mac OS X 10.6.8+, Linux with Linux kernel 2.6.28+), then the system takes over the final deletion of data from the disk, and does it automatically using the TRIM function.
TRIM implements the ability for the OS to “inform” the solid-state drive that the file has been completely deleted and the sectors occupied by it need to be cleared. Some of the first SSD models did not support TRIM, but that was so long ago (and these SSDs were so expensive) that the likelihood of getting into such a drive model is close to zero.
Don't use Windows XP or Windows Vista
New toy - new axis! And the point here is not at all new. It's just that XP and Vista don't support TRIM. In the previous paragraph, we gave the concept of TRIM, and now we need to explain how the absence of this function affects the SSD. If there is no TRIM, then after deleting the file the data will still remain on the disk. As a result, when information is written to the same sectors again, they will first have to be cleared, and only then data will be written to them. Unnecessary untimely operations -> reduced speed.
In modern operating systems, TRIM is enabled by default. The user does not need to do anything. Just leave everything as it is and enjoy the SSD speeds.
Don't fill it to capacity
In order for an SSD to operate at full speed, it must maintain approximately 25% free space on it. It sounds a little unfair: you buy an expensive SSD, it already has little space, the system sees less space in it than what is written on the box, and then they ask you to leave a quarter of the volume in reserve? Unfortunately yes. This is a feature of how SSDs work, and we don’t yet have the best widely available technologies. You will have to accept the rules for the best speed.
From the point of view of internal processes, the drop in performance with a small amount of free space can be explained as follows: a lot of free space means a lot of free blocks. When writing a file, data is written to free blocks. Little free space - many partially filled blocks and few completely free blocks. When writing a file, the system will first have to read the partially filled block into the cache, add new data to it, and then write the already modified block back to disk. And so on for each block.
The 25% limit was not taken out of thin air. This figure was arrived at by the guys from AnandTech, who conducted research on the dependence of SSD performance on its fullness.
In fact, if you use the SSD exactly where it is strongest, then having to leave a quarter of the space free won't bother you. Now we will talk about the role in which an SSD is most effective.
Do not use as storage
Buying an SSD to store a library of music and movies on it is a bad idea. The HDD speeds are quite enough to comfortably record and watch a FullHD movie from them, and listen to Losless music. SSD is needed where access and write speed is most important.
The SSD should be used as a system drive. It should have an operating system, applications and, if absolutely necessary, modern games. Nothing else.
When we understand that an SSD ideally serves as a catalyst for the most demanding processes for fast computer operation (the operation of the OS is the basis of everything, fast operation of important applications, fast reading of data from the “body” of the game), the need to fill it to capacity disappears altogether. SSD is a dedicated fast lane for only the most important things.
If you still want to use a fast SSD as storage, then just calculate the cost of rubles per gigabyte of memory for it and for the HDD.
What if you bought a new fancy ultrabook that only has an SSD, but you want to record movies? Buy an external hard drive with a USB 3.0 or Thunderbolt interface (provided that this standard is supported by the beech itself).
We hope that this information will help you start using SSDs for their intended purpose and as efficiently as possible.
