SSD disk - what is it: new horizons for data storage or just another marketing. How to choose an SSD drive: main characteristics
13. 03.2017
Blog of Dmitry Vassiyarov.
What's the big deal about solid state drives?
Hello readers. Today we’ll talk about what an ssd drive is. For some ordinary computer users, the concept of ssd - solid-state drives is new and incomprehensible.
After reading this article, you will not only understand what we are talking about, but you will also be able to maintain a conversation about this device and choose the right one for yourself. After all, old hardware becomes history and each of us sooner or later has to change it. What do modern developments look like? Read on.
What is a solid state drive?
A solid-state drive, which in English is called “Solid-State Drive” (SSD), is a storage device based on memory chips.
The situation hasn't become much clearer, has it?
I won’t bother you any longer and will explain it more simply: it’s like a flash drive, which replaces the flash drive, but has a different configuration and operating technology, and besides, it works faster and has larger amounts of memory.
If you are reading this article, most likely your computer has a regular hard drive installed: it has platters, read and write heads that spin at breakneck speed. Because of this, the screw makes noise. This cannot happen with a solid-state drive, because it is only a chip - no spinning or whirring mechanisms.
This is how HDD and SSD differ from the inside:
Types of microcircuits
Solid state drives are different depending on the specifics of data storage on chips:
![](https://i1.wp.com/profi-user.ru/wp-content/uploads/2017/03/u_41c3852655d2f22be0e9298eca31b0c7_800.jpg)
Benefits of SSD
In addition to noiselessness, a modern drive has the following advantages:
- Strength. It is not afraid of shocks and vibrations, unlike the usual hdd drive. The latter must be protected from shaking, because if the read heads collide with the spinning disks, you can say goodbye to years of accumulated photographs, reporting documentation and other important data that you store on the screw.
- Small size. Compared to conventional screws, SSDs are much lighter and smaller.
- Low power consumption.
- Incredibly high data transfer speed. This is the biggest plus.
Flaws
As they say, not without a fly in the ointment:
- High price. Most likely, this will not last long, because the cost of solid-state drives is already gradually decreasing.
- Impossibility of data recovery.
If in the event of a hard drive failure there is a chance to get at least part of the information, then there is no way to do this in an SSD - there are simply no programs or any methods.
Why? I'll explain with an example. When voltage drops in a regular hard drive, only the controller often burns out, but in an SSD drive it is located next to the memory chip.
Therefore, if something catches fire, the whole thing burns out.
- Limited number of rewrite cycles. Many may not even notice this drawback, because an MLC disk can last on average 3-4 years (this is only in theory), and the more expensive SLC can last even longer.
Moreover, during this period, as a rule, any computer requires one or another update. But there is good news: FRAM technology has already been developed that can operate in continuous read and write mode for 40 years. Isn't it weak?
In addition to the types of chips, SSDs differ in several other criteria. They need to be taken into account when choosing. Let's take a closer look.
Interface
This parameter indicates what type of connection the drive has. The data transfer speed also depends on it. Main types of busbars:
- operates at a speed of 1000 Mbit/s. This is an outdated option, but still occurs sometimes.
- SATA is a little faster (1500 Mbit/s).
- SATA2 is faster (3000 Mbit/s).
- Want to fully experience the capabilities of an SSD? Choose the 3rd generation of buses, the speed of which is twice as high as the previous one (up to 6000 Mbit/s).
- There are also devices with PCI Express connection type. Do you want to turn your computer into a super-fast machine? Give preference to PCI-e because it is even faster than SATA3. This interface is capable of transmitting data at a speed of 2 Gb/s.
![](https://i2.wp.com/profi-user.ru/wp-content/uploads/2017/03/05_w_600.jpg)
- There is one more tire. This is an M.2 interface (in theory, it should reach speeds faster even than PCI-E), but so far such drives are not very popular, and manufacturers have not yet learned how to make fast products using its potential. Another advantage is that such devices are not very large in size.
![](https://i1.wp.com/profi-user.ru/wp-content/uploads/2017/03/m.2-sata.jpg)
Form factor
This criterion indicates the size of the drive.
SSD sizes up to 3.5-inch device. They are mainly used for server computers; they are rarely used at home.
Just know that they are there :-)
Basically, the most common ones are 2.5 inch devices.
The “2242” format is a small disk with a diameter of 22x3.5x42 mm (in the image this is a disk labeled mSATA)
There are also sizes “2260” and “2280” - these are also scarf-shaped drives, connected to the M.2 interface.
Memory capacity
Are you going to install the system on a solid state drive? Then 60 GB will be enough for you. If you are using it to store multimedia data, give preference to a larger capacity. It can reach 4 terabytes, so proceed from your financial capabilities.
The most commonly chosen capacity is 240/256 GB. The minimum is 120/128 GB - this is enough to install an operating system and store a small number of media files. For other types of files, solid-state drives are usually not purchased, well, not counting the major ones :).
Performance
In addition to the speed of a flash card, another important feature is the number of I/O operations it can perform per second. In English it looks like this: input/output operations per second (IOPS). In this situation, choose according to the principle: the more, the better.
Although, by and large, these figures are arbitrary. Performance is affected by many factors (controller model, chip type, capacity, cache algorithm, etc.), so to find out the capabilities of the drive, you need to test it. But since it is impossible to do this before purchasing, you can only trust the manufacturer’s data.
Well, that’s basically all I wanted to cover in this topic. I hope I wrote it in detail and clearly. Now you know what device lies behind the abbreviation SSD and its features, so you can safely upgrade your computer.
SSD (solid state drive, solid state memory drive, solid state drive- Russian) - information storage device based on chips non-volatile memories that retain data after power is turned off. They are a relatively new type of storage media, and the first manifestation and development, non-volatile memory chips received from Flash drives and regular RAM memory.
Contains the same input/output interfaces as modern ones. IN SSD no moving parts and elements are used as in electromechanical devices (hard drives, floppy disks), which eliminates the possibility of mechanical wear.
Most modern solid state drives are based on non-volatile NAND memory. There are enterprise-class drives that use RAM memory coupled with backup power systems. This gives very high data transfer speeds, but the price of one gigabyte is very high by market standards.
There are hybrid versions of SSD and HDD drives.
They include magnetic plates for a large volume of stored information and a small volume SSD storage in one housing. The most frequently used data is stored in SSD drive and are updated as they are relevant from the block HDD. When this data is accessed, it is read at high speed from solid-state memory without accessing the slower magnetic platters.
What are SSD drives made of? .
* using example NAND memory
A solid state drive is made up of the chips themselves. NAND, a controller that brings all the functions, a volatile chip and a printed circuit board on which all this is soldered.
Sometimes in SSD drives used small battery, so that when the power is turned off, all data from the cache can be rewritten into non-volatile memory and keep all data intact. There are precedents that in drives with MLC memory when the power was turned off, some or all of the data was lost. WITH SLC memory, no such problems were noticed.
Memory.
Almost all high-, mid- and budget-class solid-state drives use non-volatile NAND(flash) memory because of its relative low cost, the ability to save data without constantly maintaining power and the ability to implement technology for saving data in the event of an unexpected power outage.
Thanks to the compact layout of the chips, manufacturers can produce SSD drives in form factor 1.8; 2.5 ; 3.5 and less if we are talking about devices without protective packaging. For example, for laptops or internal placement in a computer.
In the majority SSD drives use cheap memory that can fit in one cell more than one bit. This has a very effective effect on price finished product and contributes to the popularization of these drives. But there is MLC memory and major shortcomings. This low durability cells or more low speed writing and reading than .
SLC write down only one bit into the cell and this provides up to 10 times better durability and up to 2 times more high speed compared to MLC. There is one drawback - price drives on SLC memory approximately twice as high than the price of drives MLC memory. This is due to high production costs, and especially because SLC chips the same volume, required on average twice as much to achieve the same volume compared to MLC.
SSD controller.
Almost all indicators SSD drives depend on the control controller. It includes microprocessor, which manages all memory processes using a special firmware; and a bridge between the signals of the memory chips and the computer bus ( SATA).
Functions of a modern SSD controller:
- TRIM.
- Read-write and caching.
- Error correction ( ECC).
- Encryption (AES).
- Opportunity S.M.A.R.T monitoring.
- Marking and recording non-working blocks to add them to the blacklist.
- Data compression ( Sandforce controllers for example).
All memory controllers are aimed at parallel connected NAND memory. Since the memory bus of one chip is very small (maximum 16 bit), buses of many chips connected in parallel are used (analogy RAID 0). In addition, a single chip does not have excellent characteristics, but on the contrary. For example high delay I/O When memory chips are combined in parallel, these delays are hidden by being shared among them. And the bus grows in proportion to each added chip, up to the maximum bandwidth of the controller.
Many controllers can use 6 Gbit/s, which is coupled with controllers that support data exchange speed 500mb/s, gives a noticeable increase in performance in reading/writing and complete Unlocking the potential of SSDs drive.
Cache memory.
IN SSD drives use cache memory in the form of volatile DRAM microcircuits, similar to those found in hard drives.
But in solid-state drives it carries another important function. Part of the firmware and the most frequently changed data are located in it, reducing wear and tear on the volatile NAND memory. Some controllers do not provide for the use of cache memory, but nevertheless they achieve high speed indicators ().
Interfaces for connecting SSD.
The most common interfaces for SSD consumer class are SATA 6 Gb/s, And USB 3.0. All these interfaces are capable of providing the required throughput for any SSD drive.
In portable devices such as laptops and tablet computers, compact SSD drives with interface mini PCI-Express (mSATA ).
Advantages and disadvantages of SSD drives compared to HDDs.
Advantages of SSD drives compared to HDDs(hard drives):
- They turn on instantly, do not require promotion.
- Significantly faster random access speeds.
- Significantly faster access speed.
- The data transfer speed is much higher.
- No defragmentation required.
- They are silent because they have no mechanical parts.
- Does not create vibrations.
- More resilient in terms of temperature, shock and vibration.
- Slightly lower power consumption.
Disadvantages of SSD drives compared to HDDs(hard drives).
- Cell wear. At least in SSD drives and mechanical parts are missing, memory chips wear out (mlc ~10000 rewrites, slc ~100000 ).
- The capacity is much smaller.
- The price is significantly higher in relation to GB/$
- Inability to restore lost data after a command or simply after formatting.
Solid state drives use the command (instruction) TRIM to increase recording speed. Together with some microcontrollers, TRIM allows you to achieve a slight increase in reading speed. All solid state drives produced since 2012 have support TRIM. In earlier versions, to enable this instruction, you may need to update it with new firmware. In most cases, flashing the firmware permanently deletes all data.
SSD drives are still a completely new generation of information storage devices and they are not balanced products in all respects. However, for enthusiasts, enterprise customers and server use, they compare favorably in terms of performance, which may be a deciding factor for purchase. New round of evolution, solid-state drives will be available with mass production of memory chips Ferroelectric RAM (FRAM, FeRAM). This will improve the durability of the cells SSD drives.
But it’s not a fact that SSD storage is the future. Each new technological process, as practice has shown, reduces the read/write speed and increases the number of errors that arise, which also need to be removed using an error correction system to the detriment of performance. And for SLC this figure is acceptable, but with MLC And TLC (triple level cell) everything is very, very sad. With each new generation, without significant new breakthroughs, the speed will decrease. And by 4 nm, it will drop almost to the level HDD 2012.
In recent years, SSD drives have become increasingly accessible and cheaper. However, they still remain more expensive than traditional HDDs. So, what is an SSD, what are the advantages of using it, and how will working with an SSD differ from an HDD?
What is a solid state hard drive?
In general, solid state hard drive technology is quite old. SSDs have been on the market in various forms for several decades. The earliest of them were based on RAM memory and were used only in the most expensive corporate and super-computers. In the 90s, SSDs based on flash memory appeared, but their price did not allow them to enter the consumer market, so these drives were familiar mainly to computer specialists in the United States. Throughout the 2000s, the price of flash memory continued to fall, and by the end of the decade, SSDs began to appear in mainstream personal computers.
Intel Solid State Drive
What exactly is an SSD? First, let's talk about what a regular hard drive is. An HDD is, simply put, a set of metal disks coated with a ferromagnet that rotate on a spindle. Information can be written to the magnetized surface of these disks using a small mechanical head. Data is stored by changing the polarity of the magnetic elements on the disks. It's actually a little more complicated than that, but this should be enough to understand that writing and reading to hard drives is not very different from playing records. When you need to write something to the HDD, the disks rotate, the head moves, looking for the desired location, and the data is written or read.
SSDs, on the other hand, have no moving parts. Thus, they are more similar to the well-known flash drives than to ordinary hard drives or record players. Most SSD drives use NAND memory for storage, a type of non-volatile memory that doesn't require electricity to store data (unlike, for example, the RAM on your computer). NAND memory, among other things, provides a significant increase in speed compared to mechanical hard drives, if only because it does not require time to move the head and rotate the disk.
Comparison of SSDs and regular hard drives
So, now that we know a little about what SSDs are, it would be nice to know why they are better or worse than regular hard drives. Here are a few key differences.
Spindle spin-up time: This characteristic exists for hard drives - for example, when you wake up the computer from sleep, you may hear a click and spin-up sound that lasts a second or two. SSDs have no spin-up time.
Data access time and latency: in this regard, the speed of SSDs differs from conventional hard drives by about 100 times, not in favor of the latter. Due to the fact that the stage of mechanically searching for the necessary places on the disk and reading them is skipped, access to data on the SSD is almost instantaneous.
Noise: SSDs do not make any sound. You probably know how noisy a regular hard drive can be.
Reliability: failure of the overwhelming majority of hard drives is a consequence of mechanical damage. At some point, after several thousand hours of operation, the mechanical parts of the hard drive simply wear out. At the same time, if we talk about lifetime, hard drives win, and there are no restrictions on the number of rewrite cycles.
In turn, solid-state drives have a limited number of write cycles. Most critics of SSDs most often note this factor. In reality, during normal computer use by the average user, reaching these limits will not be easy. There are SSD hard drives on sale with a warranty period of 3 and 5 years, which they usually outlive, and a sudden SSD failure is the exception rather than the rule, it just makes more noise for some reason. For example, 30-40 times more often people come to our workshop with damaged HDDs rather than SSDs. Moreover, if the failure of a hard drive is sudden and means that it’s time to look for someone who will get data from it, then with an SSD this happens a little differently and you will know in advance that soon it will need to be changed - that’s it “aging” rather than suddenly dying, some blocks become read-only, and the system warns you about the state of the SSD.
Energy consumption: SSDs consume 40-60% less energy than conventional HDDs. This allows, for example, to significantly increase the battery life of a laptop when using an SSD.
Price: SSDs are more expensive than regular hard drives per gigabyte. However, they have become much cheaper than 3-4 years ago and are already quite accessible. The average price of SSD drives fluctuates around $1 per gigabyte (August 2013).
Working with an SSD
As a user, the only difference you will notice when working at a computer, using an operating system, running programs is a significant increase in speed. However, when it comes to extending the life of your SSD, you will have to follow a few important rules.
Don't defragmentSSD. Defragmentation is completely useless for a solid-state drive and reduces its operating time. Defragmentation is a way to physically move fragments of files located in different parts of the hard drive to one place, which reduces the time required for mechanical actions to search for them. This is irrelevant in solid-state drives, since they have no moving parts, and the time to search for information on them tends to zero. By default, in Windows 7, defragmentation for SSDs is disabled.
Disable indexing services. If your operating system uses any file indexing service for faster file retrieval (Windows does), disable it. The speed of reading and searching for information is sufficient to do without an index file.
Your operating system must supportTRIM. The TRIM command allows the operating system to communicate with your SSD and tell it which blocks are no longer in use and can be cleared. Without the support of this command, the performance of your SSD will quickly decrease. TRIM is currently supported on Windows 7, Windows 8, Mac OS X 10.6.6 and higher, and Linux with kernel 2.6.33 and higher. Windows XP does not support TRIM, although there are ways to implement it. In any case, it is better to use a modern operating system with an SSD.
No need to fill outFully SSD. Read the specifications of your SSD. Most manufacturers recommend leaving 10-20% of its capacity free. This free space must be left to use utility algorithms that extend the life of the SSD by distributing data into the NAND memory for even wear and higher performance.
Store data on a separate hard drive. Despite the price reduction of SSDs, there is no point in storing media files and other data on an SSD. It is better to store things like movies, music or pictures on a separate hard drive; these files do not require high access speeds, and HDD is still cheaper. This will extend the life of the SSD.
Install more RAMRAM. RAM memory is very cheap these days. The more RAM installed on your computer, the less often the operating system will access the SSD for the page file. This significantly extends the life of the SSD.
Do you need an SSD drive?
It's up to you to decide. If most of the points listed below suit you and you are ready to shell out several thousand rubles, then take the money to the store:
- You want your computer to turn on in seconds. When using an SSD, the time from pressing the power button to opening the browser window is minimal, even if there are third-party programs in startup.
- You want games and programs to launch faster. With an SSD, when you launch Photoshop, you don’t have time to see its authors on the splash screen, and the loading speed of cards in large-scale games increases by 10 times or more.
- You want a quieter, less power-hungry computer.
- You are willing to pay more per megabyte, but get faster speeds. Despite the reduction in the price of SSDs, they are still many times more expensive than conventional hard drives per gigabyte.
If most of the above sounds like you, then go for the SSD!
Hello friends! As they used to say in Rus': “Every merchant praises his goods” and no matter how many different articles you read about SSDs, you are unlikely to come across the same opinion. Some people read something and decided to buy a Samsung solid-state drive, some from Toshiba, while others decided to buy an OCZ Vertex or SSD at any cost. Kingston.
About a year and a half ago, my friends and I firmly decided to buy an SSD, but everyone has them, but we don’t. My friends asked me to test various SSDs and choose the best one.
Solid-state drives are not sold very well, so sellers of computer goods do not carry a lot of them, so as not to lie as dead weight in the warehouse. We also do the same, which is why I had the best-selling SSDs at my disposal at that time. The most inexpensive of the entire company turned out to be the Silicon Power V70 SSD, the test of which I left for later.
I wasn’t particularly sophisticated in my tests; I installed an operating system on each SSD, then compared the SSD and a regular HDD in the CrystalDiskMark and AS SSD Benchmark test programs. I didn’t have to prove to anyone that an SSD is better than a regular HDD. Windows installed on an SSD loaded in 4 seconds; the test programs CrystalDiskMark and AS SSD Benchmark showed the complete superiority of the SSD over a regular HDD by 3-4 and even 5 times.
I carried out all the tests on the sales floor and the information was available to customers, in short, all the test SSDs were disassembled, besides, that day was good for sales and there wasn’t even a single SSD left on the display case, well, I think I was left without a solid-state drive! And then I remembered about SSD Silicon Power - V70. In principle, I knew this good manufacturer from Taiwan, but I still wanted something else, for example Crucial or Plextor!
I also decided to test it at the end of the working day and after the tests I was a little surprised, the V70 turned out to be a great solid-state drive, in no way inferior to other SSDs I tested and sold that day. And the SiSoftware Sandra program generally awarded him first place.
Over the course of a year, wherever it didn’t work for me: on a laptop and on various stationary system units and instead of a flash drive, I carried it in my pocket and dropped it on the floor, but nothing, it still works fine.
Well, okay, enough chatter, I’ll move on to the most important part of the article, the answers to your questions about the solid-state drive, and at the end of the article I’ll give some tests that prove that an SSD for installing an operating system is just what the doctor ordered.
ALL your questions regarding SSDs.
1. What is the internal structure of an SSD? Which NAND flash memory should I buy an SSD based on: SLC, MLC or TLC?
2. Which SSD manufacturer should you prefer?
3. Is the lifespan of an SSD really limited? After how many years of use will my SSD fail?
4. Is the user at risk of losing all recorded data if the resource of the memory chips is exceeded?
5. To extend the life of the SSD, is it worth disabling hibernation, paging file, recovery, disk indexing service, disk defragmentation, Prefetch technology, and moving cache? browser and a directory of temporary files on another hard drive, and so on?
6. How much faster is an SSD than a regular hard drive?
Comparing different SSDs in terms of performance
It is important to know not only the average sequential read and write speed on an SSD, but also what is hushed up by all SSD manufacturers - the random write speed in blocks of 512 kB and 4 kB! Disk activity for most users occurs mainly in such areas!
When comparing SSDs from different manufacturers in the AS SSD Benchmark program, we can see the following result, for example:
My SSD Silicon Power V70 showed:
Sequential read and write speed 431 MB/s (read), 124 MB/s (write)
The speed of reading and writing in 4 KB blocks turned out to be 16 MB/s (read), 61 MB/s (write)
SSD from another manufacturer. As you can see, there is a high (higher than my SSD) sequential read and write speed of 484 MB/s (read), 299 MB/s (write), but there is a drop in reading/writing in 4 KB blocks, namely 17 MB/s (read), 53 MB/s (write).This means this SSD is not faster than mine, although the box of this SSD may show the numbers 500 MB/s.
SSD test in SiSoftware Sandra program
My SSD ranked first among similar models
Welcome to my blog!
An SSD drive is already becoming a mandatory attribute not only for laptops and netbooks, but also for desktop computers.
In this article I will try to understand what an SSD drive is and describe its strengths and weaknesses. We will also consider its use in home computers.
What you will learn by reading this article:
What is an SSD disk?
An SSD is a solid-state drive that uses flash memory (NAND) to store data. The abbreviation SSD can be deciphered as Solid State Disk or Solid State Drive, but the second option seems more correct to me.
An SSD drive has no mechanical or moving parts, which makes it more reliable than a mechanical HDD.
The first prototypes of modern solid-state drives were produced on the basis of RAM memory, and in order not to lose information after turning off the computer, a battery was connected to it.
Now, of course, SSD drives are made using a different technology and turning off the computer will not lead to loss of information.
What does an SSD disk consist of?
The main parts that make up an SSD are a flash memory chip, a controller, a disk connection interface, and a housing.
Flash memory chip.
Currently, modern SSDs use three types of memory: SLC, MLC and TLC.
SLC (Single-Level Cell) - one bit of information is written to each cell of this memory. The number of rewrite cycles is 100,000. It has the largest rewrite margin, but it is also the most expensive memory and is used in expensive server systems.
MLC (Multi-Level Cell) – two bits of information are written to each cell. The number of rewrite cycles is 3000. This memory is used for the production of most SSD drives, as it is less expensive and has the potential for large amounts of disk space.
TLC (Triple-Level Cell) – three bits of information are written to each cell. The number of rewrite cycles is 1000. The cheapest type of memory has long been used in the production of flash drives. It is also starting to be used in the production of SSD drives, which makes their production even cheaper, for example, Samsung 840 EVO.
The number of rewrite cycles can vary upward, it depends on the production technology, and it does not stand still.
When memory cells wear out, they become blocked, so the disk itself remains functional, it only loses capacity. But if you use it correctly, and take into account its size, then the service life of an SSD will be several years.
The main manufacturers of memory chips are Intel, Hynix, Micron, Samsung, SanDisk and Toshiba.
If we talk about the memory sizes of SSD disks, then at the moment you can find disks with a capacity of 1TB. But the price of such a disk is still too high, for example, an 800GB disk with a SATA3 interface costs about 80,000 rubles, and with a PCI-E interface, about 160,000 rubles. Not everyone wants to buy themselves a fast flash drive for that amount.
Controller.
The controller is the processor that manages read and write operations. This is the second most important element in a solid-state drive, after memory.
The controller's duties include:
Constant monitoring of the state of memory cells and blocking them when completely worn out;
Uniform distribution of files across the entire disk for uniform wear of memory cells;
Transferring data from memory to RAM memory, if available;
Compress files to speed up transfer;
The speed of reading and writing depends not only on the memory, but also on the controller. So, for example, in cheap disks, the speed of the controller may be limited if there is fast memory; as a result, the read and write speed of the disk will be lower.
SSD form factor.
SSD drives are available in different formats. There are currently five of them in total.
SATA – This is the most common type of 2.5-inch drives. They can be installed on both a desktop PC and a laptop. Only in a laptop you will have to remove a larger HDD or CD-ROM. 1.8-inch drives with a SATA interface are less common. I advise you to take SATA-3 format drives, their read/write speed is much higher than SATA-2, about 500MB/s and higher.
mSATA – As a rule, disks of this format are installed in laptops, where a special compartment is designed for them. In terms of speed, some models are inferior to SATA drives.
PCI-E – The highest read/write speed, thanks to the PCI-E bus, is shown by disks of this particular format, up to 2000 MB/s. But they are also the most expensive of the solid-state ones.
Hybrid (SSHD) – These are disks where a regular hard drive is used as the main storage device, and an SSD drive is used as cache memory. This method allows you to quickly launch applications that you use frequently. In general, the speed of such a disk is the same as that of a regular HDD, but some programs run very quickly.
USB – External drives are not very fast because the USB port is the weak link. I advise you to buy drives with a USB 3.0 interface, as the speed will be much higher than USB 2.0. But the external drive never required the same speed as the internal one. So, if speed is not so important to you, then it is better to buy a regular hard drive, which is cheaper and has more capacity.
Advantages of SSD drives.
Fast file access – SSDs have no moving head or disk and read almost instantly.
High data transfer speed – For the same reason, SSD has a very high data transfer speed.
Good shock resistance - Again, there are no fragile mechanisms and nothing to break under light impacts.
Less power consumption – There are no drives or moving parts, and much less energy is required to operate solid state devices.
Low noise level – Same story here, nothing moves or makes noise.
Disadvantages of SSD drives.
High cost of solid state drives.
Less disk space compared to HDD.
Limited data rewrite cycle.
Of course, all these shortcomings are a temporary phenomenon and soon solid-state ones will catch up and surpass mechanical ones, and they, in turn, will become hopelessly outdated.
Now, of course, you can use an SSD drive in a personal computer, but only as the main one where the system is installed, and not as storage for your files.
I will tell you how to extend the life of a solid-state drive in one of the following articles. If you have not yet subscribed to updates, you can do so now.
If you are going to buy a computer and don’t know how to choose a processor, then I recommend reading this, which describes the main criteria by which you need to choose a processor for a computer.
Good luck!