What is an SSD drive? Pros, cons and tips for choosing an SSD drive. SSD drives: pros, cons and glitches Pros and cons of ssd drives
What is an SSD? A solid-state drive (from the English Solid-State Drive, SSD) is a non-mechanical storage device made on the basis of memory chips and a control controller.
Although these devices are very compact, their scope is not limited to use in laptops, netbooks and other portable devices.
They are also installed in ordinary desktop PCs when they want to achieve maximum performance.
In addition to the main advantages of solid state drives, such as speed, compactness (size and weight), SSDs also have a number of significant disadvantages: significantly lower wear resistance and a significantly higher cost per 1 GB of capacity.
In addition to replacing the main hard disk with an SSD drive, there is a scheme for combining them, called hybrid hard drives - Solid State hybrid drive.
When using this scheme, an SSD, usually small capacity (30 GB), is used as a clipboard, less often as a separate drive (Dual Drive Hybrid System).
This layout allows you to use the advantage of flash memory - the speed of random access while maintaining a low cost of storing large amounts of data.
On the this moment SSD drives available for a wide range of consumers have the following volumes: 30/32 GB, 60/64 GB, 120/128 GB, 240/256 GB, 480/500/512 GB, 1 TB.
The main connection interface is SATA III, although laptop manufacturers have recently abandoned the use of mSATA in favor of NGFF.
The main markets for the consumption of solid state drives are server, consumer, industrial solutions.
The cost of solid state drives is gradually decreasing, if in 2013 a 128 GB SSD disk cost 70-80 dollars, now a similar device can be found for 55-65.
What is SSD - SSD architecture
SSDs can be built using non-volatile NAND SSD and volatile RAM SSD memory.
NAND SSD drives appeared on the market relatively recently, but they confidently occupied their niche in the SSD market due to their relatively low cost.
Until 2012, the advantage of NAND SSDs over conventional hard drives was only compactness and high speed of information retrieval, the write speed was significantly inferior to HDD.
After 2012, this shortcoming was eliminated, and today the read / write speed capabilities of NAND SSDs are several times higher than those of conventional hard drives, while maintaining the compactness and minimal size of the device.
NAND SSD drives are used for a wide range of user tasks.
Important! As noted above, RAM SSDs are built using volatile memory. The same memory is used in random access memory computer (RAM). This architecture is characterized by ultra-fast read, write and information retrieval speeds.
Due to the rather high cost, solutions using RAM SSD are rather narrowly focused and are used to speed up the work of large database management systems (DBMS), as well as high-performance graphics stations.
Batteries are used to solve the problem of data retention after power loss, and more expensive implementations are equipped with backup and / or online backup systems.
Advantages and disadvantages of SSD drives
Having mentioned the advantages of solid state drives at the beginning of the article, we noted only the key ones. Below will be given the most complete list of the benefits that the use of solid state drives brings to everyday tasks.
So, the advantages of SSD-drives include:
1. The absence of moving parts and, as a result, the complete absence of noise and a fairly high resistance to mechanical stress.
2. High read and write speed, which is significantly higher than HDDs and close to the bandwidth of SATA interfaces.
3. Constant value of file reading time regardless of their location, fragmentation.
4. Low power consumption.
5. Low heat generation and wide operating temperature ranges.
6. Low sensitivity to external electromagnetic fields.
7. Compactness (small dimensions, weight).
There is nothing perfect, therefore, in addition to the advantages, we will also touch on the disadvantages that a user of a computer equipped with an SSD will face:
1. Limited number of rewrite cycles. This disadvantage is typical for the NAND architecture of SSDs; it is absent in RAM SSDs. At the moment, most SSD-drives support the ability to overwrite at the level of 100 thousand cycles.
For example, a 120 GB drive with 20 GB recorded daily is 6 years old. With less daily recorded information, the service life increases accordingly.
To eliminate this shortcoming, 2 auxiliary solutions are used: load balancing, i.e. uniform recording of information in all available memory cells, thanks to a special controller, as well as the ability to monitor on-line the service life of memory cells.
When the resource of rewrite cycles is exhausted, the drive is switched to read-only mode, and all information remains available for backup. Most brand name SSDs come with a 3 year warranty.
2. Price. Although there is a clear downward trend in the cost of 1 GB SSDs, the gap in cost compared to HDDs is currently 3 times (500 GB HDDs and SSDs were selected for comparison).
It should also be noted that pricing in solid state hard drives is strictly tied to their capacity and grows in direct proportion to its increase. At the same time, the change in the price of an HDD disk from its volume is growing more slowly than SSD competitors.
3. The impossibility of recovering information in the event of a voltage drop.
Since the controller and SSD media are made on the same board, if the maximum allowable voltage limit is exceeded or if it drops, in most cases the entire SSD drive suffers, without the possibility of subsequent recovery of information.
At the same time, HDD disks in a similar situation are limited only to a burned-out controller, and the information is available for recovery.
As you can see, the disadvantages of SSD drives are non-ritic and, with the right approach, can be eliminated, providing the user with the wide benefits of using solid state drives for everyday tasks.
Relatively recently, a new type of memory has appeared on the market for computer components, which should soon completely replace the usual hard drives. SSD drives should become a new milestone in the development of personal computers.
SSD technology
The name SSD comes from English solid state drive, which in translation into Russian means - solid-state drives. At the very beginning, as soon as they appeared on the market, due to their small amount of memory and ultra-high price, they could not compete with the usual HDDs. After a short period of time, the amount of their memory began to increase rapidly, while their price, on the contrary, went down.
Against the backdrop of how SSDs began to rapidly replace the familiar HDDs, many personal computer users began to seriously think about switching to solid-state memory drives themselves.
How did SSD drives manage to gain popularity among a large number of PC users in such a short period of time? What visible advantages do they have over traditional hard drives such as HDD?
Benefits of an SSD
The main advantage of SSD is, of course, the speed of writing and data transfer. Since SSD drives are actually flash memory in their structure and structure, they simply demonstrate incredible rates of writing and information exchange. The most obvious advantage of SSDs over HDDs is the fact that booting operating system Windows is several times faster when you install it on an SSD. The computer starts up almost instantly, which positively affects the user's work efficiency and system performance as a whole. The overall increase in PC performance becomes apparent.
Such an increase in PC speed does not limit the list of advantages of SSDs over conventional hard drives. Solid state drives are much more reliable than hard drives due to the fact that their design is completely free of any moving parts. Solid state drives can easily withstand any shocks, vibrations and other negative physical impacts that may occur during transportation.
Cons of an SSD
In fairness, it is necessary to mention certain disadvantages inherent in SSD drives. Unlike hard drives, solid-state memory drives are virtually indestructible if they fail. For many PC users, such features of SSDs are decisive in favor of choosing an HDD because data loss is a really serious problem. To minimize this situation, SSD users are advised to back up all their data on a regular basis. Along with this, it is worth noting that ordinary hard drives are also far from always possible to repair and restore the information recorded on them. Based on the above information, to save your data, there is simply no other alternative than archiving and backing up your data.
From personal experience, any user can be convinced that using an SSD as the main storage medium on a PC makes the computer significantly faster. For clarity, you can compare two identical laptops. One will have a 250GB SSD while the other will run a 500GB HDD. Of course, the volume of solid-state storage media is half that of a traditional hard drive, but at the same time, the same boot of the operating system on a laptop with an SSD will take less than one minute, while a laptop with an HDD will require Windows startup about 5 minutes time.
SSD and software
In addition, there is an increase in the launch speed of any programs installed on a PC with an SSD and the speed of opening Internet pages in a browser. But it is also worth noting the multiple increase in the speed of archiving data on SSD drives in comparison with hard drives. If archiving information on an HDD takes about an hour, then on a PC with an SSD, the same information will be archived in just 15 minutes. Summarizing all of the above, we can safely say that the SSD drive greatly facilitates the work with a PC and the speed of processing large amounts of data.
The use of SSD drives in everyday life
Despite all this and the huge advantages of SSDs over conventional HDDs, they have not yet been widely used in the structure of servers and large databases, where valuable information is stored that requires reliability of its safety. All this is mainly due to the high cost of solid state drives compared to HDD hard drives, as well as the fact that SSDs cannot yet boast good durability and reliability of storing important data. So far, in practice, it has not yet been established how long SSD drives can store information without data loss. All this requires a certain amount of time, as well as the collection of averaged statistical data.
It has already become obvious to everyone that in the near future SSD drives will become significantly cheaper while their volume is growing at the same time. Soon, solid state drives will finally catch up with hard drives in all consumer qualities. As for the technical parameters, even now SSD drives are several times ahead of HDD hard drives in all respects, which makes them very attractive in the eyes of many PC users.
The above disadvantages and advantages can accurately tell whether a particular user needs an SSD solid state drive or not. Anyone who needs a fast personal computer that is able to process huge amounts of information in the shortest possible time should opt for SSD drives. But those people who care about the amount of storage media, its reliability, as well as cost, they can continue to use traditional HDD hard drives.
Should you trust SSD drives?
Regarding the issue of data and information security, regardless of the type of storage medium, whether it is an SSD drive or an HDD hard drive, any PC user should not forget about backup important information. After all, there is nothing eternal in our world, and the most reliable things tend to fail. It is always necessary to monitor and take care of the safety of important information yourself, not relying only on the capabilities of modern technologies.
Until recently, when buying a new computer and choosing the drive to install, the user had the only choice - a hard drive. HDD disk. And then we were only interested in two parameters: spindle speed (5400 or 7200 RPM), disk capacity and cache size.
Let's look at the pros and cons of both types of drives and make a visual comparison of HDD and SSD.
Principle of operation
A traditional drive, or as it is commonly called ROM (Read Only Memory), is necessary to store data even after a complete power outage. Unlike RAM (Random Access Memory) or RAM, data stored in memory is not erased when the computer is turned off.
A classic hard drive consists of several metal "pancakes" with a magnetic coating, and data is read and written using a special head that moves above the surface of the disk rotating at high speed.
Solid-state drives have a completely different principle of operation. An SSD has no moving parts at all, and its “innards” look like a set of flash memory chips placed on a single board.
Such chips can be installed both on the system motherboard (for especially compact models of laptops and ultrabooks), on a PCI Express card for desktop computers, or on a special laptop slot. The chips used in SSDs are different from what we see in a flash drive. They are much more reliable, faster and more durable.
Disk history
Hard magnetic disks have a very long (of course, by the standards of the development of computer technology) history. In 1956, IBM released a little-known computer IBM 350 RAMAC, which was equipped with a 3.75 MB storage device that was huge by those standards.
These cabinets could store as much as 7.5 MB of data
To build such a hard drive, 50 round metal plates had to be installed. The diameter of each was 61 centimeters. And all this gigantic construction could store… just one MP3-composition with a low bitrate of 128 Kb/s.
Up until 1969, this computer was used by the government and research institutes. Some 50 years ago, a hard drive of this size was quite suitable for mankind. But the standards changed dramatically in the early 80s.
5.25-inch (13.3 cm) floppy disks appeared on the market, and a little later, 3.5- and 2.5-inch (notebook) versions. Such floppy disks could store up to 1.44 MB of data, and a number of computers of that time were supplied without a built-in hard drive. Those. to start the operating system or program shell, you had to insert a floppy disk, then enter a few commands, and only then get to work.
In the entire history of the development of hard drives, several protocols have been changed: IDE (ATA, PATA), SCSI, which later transformed into the now well-known SATA, but they all performed the only function of a “connecting bridge” between the motherboard and the hard drive.
From 2.5 and 3.5-inch floppy disks with a capacity of one and a half thousand kilobytes, the computer industry has moved to hard disks of the same size, but with a thousand times more memory. Today, top 3.5-inch HDDs are up to 10 TB (10,240 GB); 2.5-inch - up to 4 TB.
The history of SSDs is much shorter. About the release of a device for storing memory, which would be devoid of moving parts, engineers thought back in the early 80s. The appearance in this era of the so-called bubble memory was met with very hostility and the idea proposed by the French physicist Pierre Weiss back in 1907 did not take root in the computer industry.
The essence of bubble memory was to divide the magnetized permalloy into macroscopic regions that would have spontaneous magnetization. The unit of measure for such an accumulator was bubbles. But the most important thing is that there were no hardware moving elements in such a drive.
Bubble memory was forgotten very quickly, and was remembered only during the development of a new class of drives - SSD.
SSDs only appeared in laptops in the late 2000s. In 2007, the budget laptop OLPC XO-1 entered the market, equipped with 256 MB of RAM, AMD processor Geode LX-700 with a frequency of 433 MHz and the main highlight - 1 GB NAND flash memory.
The OLPC XO-1 was the first laptop to use a solid state drive. And soon the legendary line of netbooks from Asus EEE PC with the 700 model joined it, where the manufacturer installed a 2-gigabyte SSD drive.
In both laptops, the memory was installed directly on the motherboard. But soon, manufacturers revised the principle of organizing drives and approved a 2.5-inch format connected via the SATA protocol.
The capacity of modern SSD drives can reach 16 TB. Most recently, Samsung introduced just such an SSD, however, in a server version and with a space price for the average layman.
Pros and cons of SSD and HDD
The tasks of drives of each class come down to one thing: to provide the user with a working operating system and allow him to store personal data. But both SSD and HDD have their own characteristics.
Price
SSDs are much more expensive than traditional HDDs. To determine the difference, a simple formula is used: the price of the drive is divided by its capacity. As a result, the cost of 1 GB of capacity in currency is obtained.
So, a standard 1 TB HDD costs an average of $50 (3300 rubles). The cost of one gigabyte is $50 / 1024 GB = $0.05, i.e. 5 cents (3.2 rubles). In the SSD world, everything is much more expensive. An SSD with a capacity of 1 TB will cost an average of $ 220, and the price for 1 GB according to our simple formula will be 22 cents (14.5 rubles), which is 4.4 times more expensive than an HDD.
The good news is that the cost of SSDs is rapidly declining: manufacturers are finding cheaper solutions for the production of drives and the price gap between HDDs and SSDs is narrowing.
Average and maximum capacity of SSD and HDD
Just a few years ago, between the maximum capacity of HDD and SSD, there was not only a numerical, but also a technological gap. It was impossible to find an SSD that could compete with HDD in terms of the amount of stored information, but today the market is ready to provide the user with such a solution. True, for impressive money.
The maximum capacity of SSDs offered for the consumer market is 4TB. Similar option at the beginning of July 2016. And for 4 TB of space you will have to pay $1499.
The base HDD capacity for laptops and computers released in the second half of 2016 ranges from 500 GB to 1 TB. Models similar in power and characteristics, but with an installed SSD drive, are content with only 128 GB.
SSD and HDD speed
Yes, it is for this indicator that the user overpays when he prefers SSD storage. Its speed is many times higher than that of an HDD. The system is able to boot in just a few seconds, it takes much less time to launch heavy applications and games, and copying large amounts of data from a multi-hour process turns into a 5-10 minute process.
The only “but” is that data from an SSD drive is deleted as quickly as it is copied. Therefore, when working with an SSD, you may simply not have time to press the cancel button if one day you suddenly delete important files.
Fragmentation
The favorite "delicacy" of any HDD hard drive is large files: MKV movies, large archives and BlueRay disk images. But as soon as you load the hard drive with a hundred or two small files, photos or MP3 compositions, the read head and metal pancakes become confused, as a result of which the recording speed drops significantly.
After filling up the HDD, repeatedly deleting/copying files, the hard disk starts to work more slowly. This is due to the fact that parts of the file are scattered over the entire surface of the magnetic disk, and when you double-click on a file, the read head is forced to look for these fragments from different sectors. This is how time is wasted. This phenomenon is called fragmentation, and as a preventive measure to speed up the HDD, a software and hardware process is provided defragmentation or ordering such blocks/parts of files into a single chain.
Principle SSD work fundamentally different from the HDD, and any data can be written to any sector of memory with further instant reading. That is why defragmentation is not needed for SSD drives.
Reliability and service life
Remember the main advantage of SSD drives? That's right, no moving parts. That is why you can use a laptop with an SSD in transport, off-road or in conditions inevitably associated with external vibrations. This will not affect the stability of the system and the drive itself. The data stored on the SSD will not be affected even if the laptop falls.
HDDs are exactly the opposite. The read head is located only a few micrometers from the magnetized blanks, and therefore any vibration can lead to the appearance of " bad sectors» - areas that become unsuitable for work. Regular shocks and careless handling of a computer that runs on an HDD will lead to the fact that sooner or later such a hard drive will simply, in computer jargon, “fall apart” or stop working.
Despite all the advantages of SSDs, they also have a very significant drawback - a limited use cycle. It directly depends on the number of memory blocks rewriting cycles. In other words, if you copy/delete/recopy gigabytes of information every day, you will very soon cause the clinical death of your SSD.
Modern SSD drives are equipped with a special controller that takes care of evenly distributing data across all SSD blocks. So it was possible to significantly increase the maximum operating time up to 3000 - 5000 cycles.
How durable is an SSD? Just take a look at this picture:
And then compare with the warranty period of operation, which is promised by the manufacturer of your particular SSD. 8 - 13 years for storage, believe me, not so bad. And do not forget about the progress that leads to a constant increase in the capacity of SSDs at an ever-decreasing cost. I think in a few years your 128 GB SSD will be a museum piece.
Form Factor
The battle of drive sizes has always been caused by the type of devices in which they are installed. So, for a desktop computer, the installation of both a 3.5-inch and a 2.5-inch drive is absolutely uncritical, but for portable devices, such as laptops, players and tablets, a more compact version is needed.
The 1.8-inch format was considered the smallest serial version of the HDD. This is the disc used in the discontinued iPod Classic.
And no matter how hard the engineers tried, they failed to build a miniature HDD-hard drive with a capacity of more than 320 GB. It is impossible to break the laws of physics.
In the world of SSD, everything is much more promising. The generally accepted 2.5-inch format has become such not because of any physical limitations that technologies face, but only because of compatibility. In the new generation of ultrabooks, the 2.5 '' format is gradually being abandoned, making the drives more and more compact, and the cases of the devices themselves thinner.
Noise
The rotation of disks even in the most advanced HDD hard drive is inseparably linked with the occurrence of noise. Reading and writing data sets the disk head in motion, which rushes around the entire surface of the device at insane speed, which also causes a characteristic crackle.
SSD drives are absolutely silent, and all processes occurring inside the chips take place without any accompanying sound.
Outcome
Summing up the comparison of HDD and SSD, I want to clearly define the main advantages of each type of drive.
Advantages of HDD: capacious, inexpensive, accessible.
HDD Disadvantages: slow, afraid of mechanical influences, noisy.
Advantages of SSD: absolutely silent, wear-resistant, very fast, have no fragmentation.
Disadvantages of SSD: expensive, theoretically have a limited service life.
Without exaggeration, we can say that one of the most effective methods for upgrading an old laptop or computer is installing an SSD drive instead of an HDD. Even with the latest version of SATA, you can achieve a threefold increase in performance.
Greetings to those who cannot decide which is better SSD or HDD.
In this article, we will weigh the pros and cons of both devices, making it easier for you to choose. I advise you to read it also to those who are not going to buy a drive yet, but do not know why there are so many disputes between adherents of one and another type.
Size and weight
As you understand, one chip takes up much less space, even inside a protective case, than many elements in it, which is why it is lighter. The weight of the first is no more than 100 grams, and the second, even with a small form factor of 2.5 inches, up to 800 g.
So if you have a laptop and carry it with you all the time, consider this way to lighten your bag.
Noise and impact resistance
The absence of mechanical parts in the SSD has affected not only the reduction in weight and size, but also the noise emitted. There is simply nothing to rattle about in it.
Also, this advantage makes the solid-state device resistant to shaking. While moving parts in hard drives do not tolerate vibrations and shocks. If the device falls, the read head can damage the disc and you will lose important information forever...
Power consumption and heat dissipation
What other advantage does the lack of moving parts in an SSD provide? It consumes less electricity, therefore it heats up less. Compare for yourself: at maximum load, it consumes only 2 watts, while its mechanical competitor - 7 watts.
In addition, the latter, when it works for a long time, may need an additional source of cooling, which will add more kilowatts to your electricity bill.
Speed
During the existence of hards, not only their appearance but also performance. Yes, the read head spins magnetic disks at a frantic speed, but as it was originally 7400 rpm, it has survived to this day. True, a hard one with an indicator of 10,000 rpm was also released. And since then it's been quiet.
What do these numbers mean in terms of megabytes? The first is about 120 Mb / s, the second is about 180 - 200 Mb / s. By today's standards, this is not enough. More demanding operating systems and programs have appeared, so the screws spend a lot of time loading them.
For clarity, let's compare how much faster an SSD processes small blocks of data than an HDD. After all, it is with them that we deal with when performing the most common tasks on a computer. Let's take blocks of 4 KB and get, on average, the following indicators:
- With read operations, the speed of the chips will be 63.6 Mb / s, and disks at 5.4 thousand rpm - 0.68 Mb / s, which is 94 times slower.
- During write operations, the first ones work at a speed of 139 Mb / s, and the second - 0.78 Mb / s, which is 178 times less.
Digression on the topic
The numbers are impressive, aren't they? By the way, have you noticed how much time it takes you to boot the system from hard? Usually, about 2 minutes. With an ssd chip, it takes about 10-15 seconds.
This is because when starting the OSes, the first ones spend time searching for the right sectors, moving the reading head from side to side on the plate. The second, in turn, is quite simple to get data from a specific block.
Do you know why Apple products are famous for not slowing down? Because it is equipped with solid state drives. If you get the chance, for comparison, try to put, for example, an Apple M.2 SSD instead of your HDD without changing the operating system and anything else. You'll see how important a hard drive is to a computer's responsiveness. You won't have to deal with the "Not Responding" phenomenon in the Task Manager.
Disadvantages of SSD
Prior to this, a solid-state device has always been in a more advantageous position than a mechanical one. Nevertheless, it also has several disadvantages over its rival:
- Capacity. If the memory of modern screws is calculated in terabytes, then among the SSD the most popular models are 120 GB and 240 GB. Therefore, they are more often used only for installing the OS.
- Price. The cost is constantly changing, so I will not name the numbers. I can only say that with the money that you pay for a 60 GB SSD, you can buy a 1 TB HDD.
- The number of rewrite cycles. In general, this shortcoming does not really affect the situation. Yes, you can overwrite information a limited number of times (up to 10,000). However, these resources will last you for 20 years. You are more likely to change a computer than a drive. But it is worth noting that there is no overwriting limit in the HDD.
- Reliability. A solid state device is afraid of power surges. Due to a strong drop, it can burn out completely, and you will lose all data. Under similar circumstances, only the controller in a hard disk will fail, which is not related to the information in the storage.
In general, it is difficult to predict the service life of one and the other device, since external conditions and operating features largely influence this.
Finally
If you are considering whether to buy an SSD or not. Then answer the question first, for what purposes do you need it?
- If you want to speed up iron. For example, for games or work with heavy programs (graphic editors, etc.), or you are simply tired of waiting for a long time until the system boots up, take it.
- If you just need a data storage - give preference to hard.
Are you wondering if it is possible to combine both drives in one computer? Undoubtedly. The ideal option is when the SSD is installed under the system, and the HDD is for storing information.
That's all.
I think my reasoning was useful to you.
A few years ago there was a real revolution in the field of data storage - the first mass drives appeared that used flash memory chips to store information. Unfortunately, it turns out that this whole revolution has passed by the vast majority of users. Therefore, the general advantages and disadvantages of these revolutionary drives will be considered in this article.
Initially, the cost of SSD drives was sky-high, but by now they have become very affordable for a wide range of users. Often one has to face a misunderstanding of exactly what contribution to the speed of a computer a hard drive makes. It is especially upsetting that people who are directly connected with computers by occupation often suffer from this misunderstanding: system administrators, salespeople and purchasing planning departments.
As a rule, during slow operation, they sin on anything, but not on the data storage subsystem, and you can often find a situation where, when buying a new computer with a top-end processor and video card, a hard drive is installed from the old one. Or a large disk is bought, but from energy-saving series - they are cheaper, do not make noise and do not heat up. However, they have a drawback - extreme slowness.
The problem of slow disks appeared a long time ago, if we compare the progress of computer components over 10 years, it turns out that such components as a processor, memory, video cards have increased their speed by tens to hundreds and even thousands of times, but hard drives have only increased in volume. No, of course, the speed has also increased, for example, in 2000, the linear reading speed of an average disk was 30-40 Mb / s, and today it is already 120-150 Mb / s. With some other technical tweaks, this can all be called progress, if not for one nuance: as a rule, when loading and running programs, you need to read and write several hundred files that are physically located in different places on the disk platter, and for this you need to mechanically move the read-write heads . But this part of the work has not changed at all and moving the heads takes the same amount of time as it did 10 years ago. The sad thing here is that the bulk of the work falls on reading small files or blocks of data. This leads to the fact that the real speed of the exchange with the disk under some circumstances can be reduced to 5 Mb / s instead of the promised 150. Isn't it a strange and unexpected situation? As a result, we get a familiar situation for everyone: the disk crunches its heads, but nothing really happens.
Advantages.
The advantage of SSD drives is that there are no moving parts. In fact, they consist of a main controller and flash memory chips connected to it. If we take work with a regular USB flash drive as a standard, then we can recall that, as a rule, the read speed is always higher than the write speed - this is a feature of flash memory. At the same time, one single memory chip does not have an impressive speed. The task of the SSD disk controller is precisely to write incoming data in parallel to several chips.
The acceleration compared to traditional disks is due to the fact that large files are read and written in parallel on several chips. Working with a large number of small files or blocks of data occurs simultaneously, because. the drive has no heads to move, and the controller can operate multiple memory chips in parallel.
Of course, looking at the price and volume, one can doubt whether it is really worth the money. Often the advantage is compared by the operating system boot time - this is of course an indicator, but the time difference in this case will depend on many factors, and the thought arises that you can wait, because the computer turns on 1-2 times a day. A solid state drive shows its main power in loading programs and parallel operation of a disk with several programs. Again, someone will say that this is not my case, but this actually happens to everyone.
Let's consider a typical situation. You boot the computer, after the desktop appears in the lower right corner, the icons of your programs begin to slowly appear: antivirus, skype, and other smaller ones. Sometimes a window of the next program appears, in which its contents are slowly drawn ... here you already want to launch the browser and nothing prevents you from doing it. Only now it will start in a few seconds, or even longer. In such a situation, many programs simultaneously access the disk and most of the time it is busy moving heads in search of the next file. At the same time, the real speed of work drops to obscene values - the disk is overloaded, the operating system needs to process much more data than the disk can physically, so a long queue of jobs appears. At such moments, the computer almost does not respond to user actions, and some applications may receive a message stating that they are not responding, that is, they are “hanging”. Previously, you always had to wait ... but now there is a way to avoid waiting.
When using an SSD, loading modern operating systems (Windows 7/8) is different. The vast majority of programs will load while the "welcome" screen is displayed. Moreover, it will take many times less time, because. Parallel work with a high load is the strong point of SSD. Then a desktop will appear with programs already downloaded, some may still continue to download, but if you want to launch the browser, it will open in the worst case in a couple of seconds, as if the computer is not busy with anything.
In practical work, there are practically no delays for user actions, compared to conventional HDDs. Resource-intensive applications load many times faster. In general, the acceleration of the computer turns out to be very noticeable, there is also a human aspect to it - the annoyance from the waiting process grows much faster than the waiting time. The matter is aggravated by the fact that the expectation in this case does not allow switching to another task. For example, waiting for a transport or a person, you can wait 10 minutes without problems, 20 - already nervous, and after half an hour even the most patient will be furious! At the same time, the waiting time increased only 3 times. That is why accelerating the loading speed of ordinary practical tasks by about 5-10 times gives a feeling of instantaneousness. Where before you would have to wait 2-3 seconds, now you do not need to wait at all. And the periods of long waiting are reduced at times and do not have time to cause irritation.
Also, the advantages include shock resistance and a wide range of operating temperatures. It is these two factors that usually kill laptop drives.
So, the advantages include the following:
The speed of work, which is even theoretically unattainable with conventional drives
Resistance to adverse external factors
Very low power consumption
Overall reliability due to no moving parts
Flaws.
No matter how great technology is, there will always be downsides. In the case of SSDs, the first factor is price. For the same price, you can currently buy a classic drive with 20 times the capacity. There is nothing to hide - the temptation here is great, because. most likely a person is buying an SSD for the first time and has no idea how much the feeling of working on a computer changes when it is available. There are other reasons as well, such as myths about the alleged unreliability of solid state drives and that flash memory quickly fails when writing, because. has a limited resource. Myths will be discussed later. In the meantime, I would like to say that the vast majority of SSD users do not regret the purchase, but on the contrary, this purchase is the most significant upgrade. Sometimes it comes to incidents when a person constantly uses a computer with an SSD, and then after a couple of months he sits down at an average ordinary laptop and ... does not understand what is happening! He starts looking for the reason for such slow work, but there is none, everything just works as it should, and the only reason is that you quickly get used to the good.
The second disadvantage is a relatively small volume, at the moment it makes sense to purchase a disk with a size of 128-256GB. In most cases, this is enough to accommodate the operating system and programs that require increased performance. It is better to choose the size with a margin. To maintain high speed characteristics (especially recording), it is necessary that the disk as a whole has about 8GB of free space. Here you can of course be indignant that the place is expensive, but after all, for ordinary disks there is a recommendation of 10% free space for each partition, otherwise terrible file fragmentation begins. But SSD drives are not subject to file fragmentation at all, and the defragmentation process is useless for them and, one might say, a little harmful. The specified amount of free space required is approximately the same for any model and is needed for the disk as a whole, and not for each partition.
Some technical features are also a disadvantage. To begin with, for the SSD to work, it is necessary to set the operating mode of the SATA controller to AHCI in the BIOS of the computer. Older motherboards may have IDE installed by default. For classic drives, the difference is almost imperceptible, but for solid-state drives it is important.
AHCI mode allows the disk to work in multi-threaded mode, and this is precisely the main advantage of the SSD. Also, this mode is necessary for the operation of the special TRIM command, which is issued by the operating system to clear disk space.
It is necessary to dwell on the TRIM command in more detail. The fact is that when you delete a file from the SSD, the freed space cannot be immediately used to write another file. First, it must be cleared, roughly speaking, rewrite it with zeros. The cleanup process is slower than the payload write itself. To ensure that recording is always fast, the operating system tells the disk which blocks can be cleared, but for the disk this is not an order, but only a recommendation, and it cleans up what is called “in its free time”. If the TRIM command does not work for some reason, then this will result in a decrease in the write speed, say, from 400 to 200 MB / s. Still fast, but annoying. All this does not affect the speed of reading.
The following conclusions can be drawn from the above features:
AHCI mode required for fast operation
You need an operating system that supports the TRIM command, such as Windows 7/8.
Earlier Windows operating systems (Vista, XP) do not support the TRIM command, but there is a way out. The easiest way is to buy an SSD that can independently maintain the write speed at a decent level. So far, among consumer disks, only Plextor disks can do this, and even then with reservations. They do not clean up all the free space for fast recording as a TRIM command, but only 5-10 GB, since in practice this is almost always enough.
The disadvantage is still the problem of creating RAID arrays. The point here again is the TRIM command and the drop in write speed without it. Intel chipsets have only recently started to support disk cleanup for RAID 0 (striping). Unfortunately, for more practical RAID 1 or RAID 5 configurations, TRIM is not supported, with consequences. But it is these levels that are used in workstations and small servers for reliability. The way out of the situation is the same as with the old operating systems - so far only Plextor drives. Judging by the tests, the OCZ Vertex 150 are able to restore performance themselves, but they are released relatively recently and nothing is really known about their reliability.
As with ordinary disks, there are frankly unsuccessful device models that fail in huge numbers. This often happened in the first year and a half of the mass appearance of SSDs on sale. Now the situation has stabilized and we can already say that solid-state drives in general are noticeably more reliable than conventional ones.
If a disaster suddenly happened, then in the event of a sudden breakdown of the SSD, recovering data from it is a very difficult task, but possible. But if you mistakenly delete the file, then within a few seconds or minutes the TRIM command will work and the data in the file will be physically reset, and in this case the information cannot be restored by any means.
Disadvantages and features must be known and remembered about them. Moreover, most of them are not critical or acceptable, and the advantages outweigh the disadvantages.
Myths.
The peculiarity of myths is that they greatly exaggerate the true state of affairs, but the speed of their spread is truly amazing. A person may not know anything about SSD, except of course myths. Let's go through the list:
SSDs are not reliable
This myth appeared during the formation of the market. This is mainly the merit of OCZ with the Vertex 2 and Agility drive lines, as well as the early Vertex 3 models. They just died in batches, but were relatively inexpensive and at that time almost the most common. Therefore, at a general glance, a sad picture of general insecurity was seen. It's just that these were discs with frank imperfections and, apparently, the final testing was entrusted to the buyers. Devices from other manufacturers for the most part work to this day. And the disks of other lines of the OCZ company were not seen in an open marriage.
Flash memory has a limited resource and quickly fails
Rumors and the manufacturers themselves are to blame for this myth. This myth is refuted by surprisingly enthusiasts and not by the manufacturers themselves. The resource is really limited. Modern disks use MLC flash (2 bits per cell) and TLC (3 bits per cell) will become widespread in the future.
MLC has a guaranteed resource of 3000 rewrite cycles. That is, with a storage capacity of 128GB, we get:
128GB*3000=384000GB - theoretical write limit
For operation within a reasonable period of 5 years, we get:
384000/5/365=210Gb/day=2.5MB/sec – what can be recorded at such speed for 5 years around the clock?
It should be noted that in reality more data is written to the disk than there is. There is service information and wear-leveling algorithms that do not allow you to constantly overwrite the same memory blocks, but from time to time transfer files that are dead weight to more used areas, and the freed space is used for new records. And so in a circle. In practice, in the worst case, for each gigabyte of useful data, a maximum of 1.5 GB is written to memory.
The calculation above was carried out for a 128GB disk, and for 256 and 512, the recording resource will be 2 and 4 times larger, respectively, due to more memory.
For most manufacturers, the terms of the warranty stipulate that the warranty is 3 years or 35TB of recorded data (often regardless of the size of the disk), which is approximately 20GB of recording per day. Of course, this is reinsurance, and the real resource approximately corresponds to the theoretical values and this has been proven by enthusiasts who disabled more than a dozen SSDs by constant recording in order to find out the true state of affairs.
For those who are afraid and think that the recording on their computer is hundreds of gigabytes a day, a program was created SSDReady, it considers the amount of information written to the disk. But I must warn you that when calculating a record, it has an error of 10 percent, and also when estimating the lifetime of a disk, it uses the official values of the record resource, which, as mentioned earlier, is usually 35TB. But for a general assessment of the number of records, this utility is best suited. Even worse TLC type SSDs with 1000 rewrite cycles, in practice, provide overwriting of 100TB of information for a 128GB model.
As a result, it can be said about the flash memory myth that no one has yet been able to use the entire recording resource in practical use. With an average use, it is really very difficult to record even 20GB per day. Of course, if you are professionally engaged in serious graphics packages with large amounts of photo-video data, then it is likely that in 3 years you will be able to get close to the limit with incredible efforts. True, in this case, wear will be fully justified, because. data processing will be accelerated, you can also justify the wear and tear when using an SSD in a small but loaded server. Of course, there are also special SSDs with an increased resource, but their performance is usually noticeably lower, and the cost allows you to buy about 3-5 disks for normal use.
The operating system must be configured to use the SSD: transfer (or disable) the paging file, temporary program folders, disable hibernation, etc.
Such tips are designed to save the recording resource, and it is almost impossible to use it in practice, even if you try hard. In addition, such tips can even seriously reduce performance and affect stability. If Windows 7/8 is installed on the disk, then absolutely nothing needs to be done (except for activating the AHCI mode in BIOS), the operating system itself will understand that this is an SSD disk and make some optimizations. If the operating system is copied from a regular disk to an SSD, then it’s really worth using some tips and at least check if the TRIM command is enabled and disable scheduled defragmentation on this partition, if it is enabled.
On this, I hope the main myths are dispelled.
In conclusion, I’ll say that for sure I won’t be able to convince everyone, but people who started using SSD drives for the operating system and programs now only see the transition back to classic hard drives in nightmares. And the myths about unreliability and rapid wear are dispelled by themselves in the first months of use.
If you have any questions, do not hesitate to write comments.
