Содержание
- SSD vs. HDD: Know the Difference
- What is a HDD?
- What is an SSD?
- SSD vs HDD: which is best for your needs?
- What is a traditional hard disk drive (HDD)?
- What is a solid state drive (SSD)?
- SSD vs HDD: price
- SSD vs HDD: capacity
- SSD vs HDD: speed
- SSD vs HDD: other considerations
- Жёсткие диски. HDD или SSD?
- TechRadar Newsletter
- SSD vs. HDD: What’s the Difference?
- HDD and SSD Explained
- A History of HDDs and SSDs
- The Advantages and Disadvantages of SSDs and HDDs
So, HDDs are good for storing lots of large files, which makes them good for holding photos, videos and games.
SSD vs. HDD: Know the Difference
What’s the difference between SSDs and HDDs? Solid state drives and hard disk drives are similar in their physical specifications, but they store data very differently. There are advantages and disadvantages to each type of drive, and deciding on which type is right for you comes down to how you use your computer. Our guide to HDD vs. SSD shows you how each type of storage drive works and what it means for you.
What is a HDD?
The technology behind hard disk drives is well known and well tested. Hard disk drives have been around for more than 50 years, steadily increasing their storage capacity and decreasing their physical size. HDDs rely on spinning disks, or platters, to read and write data.
How hard disk drives (HDD) work
Hard disk drives consist of one or more magnetically sensitive platters, an actuator arm with a read/write head on it for each platter, and a motor to spin the platters and move the arms. There is also an I/O controller and firmware that tells the hardware what to do and communicates with the rest of the system.
Each platter is organized into concentric circles called tracks. Tracks are divided into logical units called sectors. Each track and sector number results in a unique address that can be used to organize and locate data. Data is written to the nearest available area. There is an algorithm that processes the data before it’s written, allowing the firmware to detect and correct errors.
The platters spin at pre-set speeds (4200 rpm to 7200 rpm for consumer computers). Those speeds correlate to read/write rates. The higher the pre-set speed, the faster a hard drive will be able to read and write data.
Reading and writing
Each time you ask your computer to retrieve or update data, the I/O controller tells the actuator arm where that data is located, and the read/write head gathers the data by reading the presence or absence of a charge in each address. If the request was to update the data, the read/write head changes the charge on the affected track and sector.
The time it takes for the platter to spin and the actuator arm to find the correct track and sector is known as latency.
Drawbacks
The drawbacks to HDDs are a result of the mechanical parts used to read and write data, as physically finding and retrieving data takes more time than electronically finding and retrieving data. The mechanical parts can skip or even fail if they are handled roughly or dropped. This is a concern in laptops, but not as much in desktops. HDDs are also heavier and use more energy than comparable SSDs.
Benefits of a HDD
The benefits of a hard disk drivs are that they are a proven technology, and are frequently less expensive than a solid state drives for the same amount of storage. Currently, HDDs are also available with more storage space than SSDs.
What is an SSD?
Solid state drives use flash memory to deliver superior performance and durability. Because there are lots of small, moving parts inside your hard drive — magnetic heads, spindles, and spinning platters — it’s easy for things to go wrong and you could lose your important data. Without moving parts, SSDs are more durable, run cooler and use less energy.
How solid state drives (SDDs) work
SSDs can be thought of as large USB drives; they use the same base technology. NAND, the technology in solid state drives, is a type of flash memory. At the lowest level, floating gate transistors record a charge (or lack of a charge) to store data. The gates are organized in a grid pattern, which is further organized into a block. Block size can vary, but each row that makes up the grid is called a page.
An SSD controller performs several functions, including keeping track of where data is located.
Reading and writing
Updating data is more complex for SSDs. All the data in a block must be refreshed when any portion of it is updated. The data on the old block is copied to a different block, the block is erased, and the data is rewritten with the changes to a new block.
Each time you ask your computer to retrieve or update data, the SSD controller looks at the address of the data requested and reads the charge status.
When the drive is idle, a process called garbage collection goes through and makes sure the information in the old block is erased and that the block is free to be written to again.
There is another process called TRIM that informs the SSD that it can skip rewriting certain data when it erases blocks. Because there are a finite number of times any block can be rewritten, this is an important process that prevents premature wear on the storage drive.
To further prevent wear on the drive, there is an algorithm to make sure that each block in the drive gets an equal amount of read/write processes. This process is called wear leveling and happens automatically as the drive is working.
Because the read/write process requires data movement, SSDs are usually overprovisioned with storage; there is always a certain amount of the drive that is not reported to the operating system, and not accessible to the user. This allows room for the drive to move and delete items without affecting the overall storage capacity.
Drawbacks
SSDs are newer technology, and as such, are more expensive than HDDs. Although they are catching up, it can be harder to find large-capacity solid state drives. HDDs can be as much as 2.5 times larger.
Benefits of an SSD
Why choose a solid state drive? SSDs deliver faster load times for games, applications, and movies. Because of the technology they use, SSDs are lighter and better able to withstand movement and droppage. In addition, solid state drives use less energy, allowing computers to run cooler.
One of the biggest benefits of an SSD is how much faster they are than HDDs. For example, the Crucial P5 is our fastest NVMe SSD, delivering impressive read/write speeds up to 3400/3000MB/s. Even portable SSDs are faster than HDDs. With read speeds up to 1050MB/s 1 and capacities up to 2TB, the X8 is up to 100x faster than USB flash drives 2 and up to 7.5x faster than traditional hard drives 2 .
Is an SSD a hard drive?
Put simply, an SSD isn’t the same as a hard drive. Hard drives use magnetically sensitive platters which are moved by a motor, whereas an SSD uses flash memory without any moving parts, meaning they are faster.
SSD vs HDD: which is best for your needs?
Our SSD vs HDD guide will explain the pros and cons of traditional hard drives (HDD) and solid state drives (SSD) to help you choose which one is best for your needs. Also, if you’re new to tech and want to know the better option between the two storage types, you’ll want to first learn what each does before asking which is better.
If you’re worried about whether you should get an HDD vs SSD, you’ve come to the right place. The first step in the decision is actually understanding the difference between a traditional hard drive and an SSD, which we’ll detail further in the guide. It’s important you know the difference so you understand how it will function in your tech, no matter if you’re upgrading a laptop or desktop PC or looking to buy an entirely new device.
Desktop PCs are at a bit of an advantage in the SSD vs HDD debate because they’re actually capable of using both in different capacities. You can install both of these hard drives in your tower, but it can get a little confusing if you don’t know what each drive does best. Our guide will help you identify the best ways to maximize the performance of your new drive and how to best get it connected to your PC.
Traditional hard drives and SSDs both have advantages and disadvantages to them, which we’ll also discuss in our guide. Both can have massive storage capacities capable of handling all of your files, but the advanced tech in an SSD might not make it feasible for you to install in your PC. Conversely, HDDs aren’t always as reliable as SSDs, so that will also factor into your decision of which works best for you.
Whether you’re looking to buy a new computer or laptop equipped with an SSD or hard drive, or are simply researching to see how you can give your existing setup an extra boost, we can help you make that decision. Once you know the ins and outs of an SSD vs HDD, you’ll have a clearer understanding of what your machine is capable of running and what will suit you best.
After you’ve finished our guide and have a better understanding of what an SSD is and how it differs from a traditional hard drive, we’ve got some buying guides that can help you pick new hard drives. Whether you’re looking for the cheapest SSDs or the best deal on HDDs, we’ve found it all to make your life a bit easier.
What is a traditional hard disk drive (HDD)?
If you have a desktop PC it will most likely have a traditional hard disk drive, on which the operating system, along with any applications you install, and your files and folders, are stored.
A traditional hard drive contains a circular disc – known as a platter – that stores your data. The disc spins, allowing the read-write arm to read data on the disc (or write data to it) as it passes.
The faster the platter spins, the faster the hard drive works, which can impact how quickly your operating system responds, and how long it takes applications installed on the drive to load and open.
Older hard drives use an IDE port to connect to the motherboard of a PC, but most modern hard drives use a SATA connection. The most recent version of SATA, SATA III, is found on modern motherboards, and enables the fastest possible data transfers for a HDD.
What is a solid state drive (SSD)?
A solid state drive (SSD) is newer storage technology, but it’s still been around for a while now, and if you have a modern laptop, it’s likely that it uses an SSD.
As the name suggests, an SSD – unlike a traditional hard drive – has no moving parts. Instead, it uses NAND flash memory. The more NAND (Negative-AND) memory chips an SSD has, the more storage capacity it has. Modern technology allows SSDs to have more NAND chips than ever, which means SSDs can have capacities similar to HDDs.
Many SSDs come with SATA III ports, which means they can be easily installed in place of a HDD, and many also come in the 2.5-inch format that smaller hard drives also come in. However, the maximum data throughput of SATA III is 600MB/s, and while this is fine for HDDs, SDDs are capable of much faster speeds, which means if you have an SSD with a SATA III connection, the drive’s performance is actually being held back by its SATA connection.
To avoid that bottleneck, you can get SSDs that have a PCIe connection. These drives slot into the PCIe lane of a motherboard, enabling much faster speeds. However, if you have a smaller motherboard, or you use your PCIe lanes for other devices, such as graphics cards or sound cards, then you may not want an SSD taking up a lane.
Another increasingly common connection for SSDs is the M.2. If your laptop uses an SSD, it’s most likely using an M.2 connection, and most modern desktop PCs have motherboards with an M.2 port. M.2 SSDs are typically smaller than other SSDs, which means they can be easily installed without impacting your other components.
NVMe (Non-Volatile Memory Express) is the newest SSD technology, and offers incredibly fast data transfer speeds.
SSD vs HDD: price
When you’re choosing between an SSD and HDD, the first big difference you’ll notice at first is the price. SSDs are typically more expensive per gigabyte than traditional hard drives.
However, it’s worth noting that some SSDs are more expensive than others. Older SATA III SSDs are cheaper than M2 and PCIe SSDs, and because the technology has been around for a while, certain SATA III SSDs aren’t all that more expensive than a traditional hard drive.
Check out our best cheap SSD deals guide for help finding the best price for an SSD.
If you want the most capacity for the least amount of money, HDDs are the way to go. Manufacturing processes for traditional HDDs mean they’re now relatively cheap to produce, which makes them more affordable.
You can get some large HDDs for very low prices, but if you’re keeping important data on the drives, it’s best to check out user reviews and reports about their reliability.
We’ve also got a guide on the best cheap hard drive deals, which can help you to bag a bargain.
SSD vs HDD: capacity
Closely tied to the price when comparing SSDs and HDDs is the capacities of the drives. Generally, if you’re after a lot of storage space, HDD is the way to go.
HDD capacities range from 40GB up to 12TB for commercial hard drives, while there are even larger capacities for enterprise use. These days you can get a 2TB hard drive for an affordable price, which offers you plenty of space. HDDs around the 8TB to 12TB size are primarily used for servers and NAS devices, where you need a lot of space for holding backups.
Generally, we’d recommend having several smaller hard drives rather than a single large hard drive. This is because if the drive fails, you may lose all your data – if your data is held across several drives, if one drive fails, you won’t lose everything.
So, HDDs are good for storing lots of large files, which makes them good for holding photos, videos and games.
In the past SSDs generally weren’t capable of such large capacities, but thanks to advances in technology you can now get SSDs with terabytes of storage. However, this comes at a premium, and large SDDs often come with prohibitively high price tags.
If you can, it’s a good idea to go for a smaller SSD, maybe around 160GB–256GB, to hold programs such as your operating system, for which you want to take advantage of the SSD’s higher speed, and then use a HDD to store other files where speed isn’t as important.
SSD vs HDD: speed
In the match-up between SSDs vs HDDs, speed is where we really begin to see a difference. Solid state drives have always been much faster than traditional hard drives, but with SSD technology advancing all the time, and the SATA III bottleneck removed, the difference is now starker than ever.
First, let’s look at HDD speeds. Because these drives using a spinning platter, the speed of the drive is largely dependent on the RPM (revolutions per minute) the drive is capable of – and the higher the RPM, the faster the drive can perform. Many budget hard drives have an RPM of 5,400 RPM, which is the slowest speed modern hard drives are capable of – you’re better off going for a drive that can achieve 7,200 RPM, which is what most modern HDDs will be rated at.
You can get higher-RPM drives, up to 10,000 RPM and even higher, but these are rarer and more expensive.
SSD and HDD speeds are measured in MB/s (megabytes per second) for both read (how fast the drive can read data) and write (how fast data can be written to the drive).
There are other factors in play that determine HDD speeds, such as capacity, but in general a SATA III hard drive at 5,400 RPM will have speeds of around 100MB/s, while a 7,200 RPM will be 150MB/s.
Because SSDs don’t have any moving parts their speeds aren’t dependent on RPMs, but on the technology – and the data connection – of the drive.
A solid state drive with a SATA III connection should achieve around 550MB/s read and 520MB/s write speeds, though some will be faster – but will max out at 600MB/s.
So, even with a SATA III connection, which limits the speed of SSDs, you’re getting around four times the speed of traditional hard drives. However, if you use one of the better-optimized connections for SSDs, the speed difference really opens up.
Average speeds for PCIe/M.2 SSDs range from around 1.2GB/s up to around 1.4GB/s – and if you’ve got the budget there are even some that can reach 2.2GB/s.
So, you’re looking at around 10 times the speed if you go for one of these SSDs. When it comes to speed and performance, SSDs are definitely the way to go.
SSD vs HDD: other considerations
There are other things you should consider when thinking about whether to buy an SSD or HDD. For example, because SSDs don’t have any moving parts they’re more robust, which makes them a better choice for laptops and other mobile devices.
Жёсткие диски. HDD или SSD?
An SSD can also use less power than a HDD, which means laptops may benefit from longer battery lives when using an SSD – although this will depend on the kind of SSD you use, and what you use it for.
So is an SSD or a HDD best for you? While SSDs are faster, more robust and more power-efficient, HDDs are more affordable – especially when it comes to larger capacities.
As we mentioned earlier, if you have the option then it may be worth getting a smaller SSD for your operating system and apps, along with a HDD to store your files. There are also hybrid drives, known as SSHDs, which offer the best of both worlds, with the speeds of SSDs and the capacities of HDDs in a single drive, and which are worth considering if you don’t have the space in your device for multiple hard drives.
- Best SSDs 2022: the top solid-state drives for your PC
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SSD vs. HDD: What’s the Difference?
Do you like your storage cheap and plentiful, or fast and shockproof? Here’s how to choose between a traditional hard drive and a solid-state drive in your next PC.
By Tom Brant
Deputy Managing Editor
My Experience
I’m the deputy managing editor of the hardware team at PCMag.com. Reading this during the day? Then you’ve caught me testing gear and editing reviews of laptops, desktop PCs, and tons of other personal tech. (Reading this at night? Then I’m probably dreaming about all those cool products.) I’ve covered the consumer tech world as an editor, reporter, and analyst since 2015.
Updated August 26, 2022
https://www.pcmag.com/news/ssd-vs-hdd-whats-the-difference
(Credit: Bob Al-Greene)
If you bought an ultraportable laptop anytime in the last few years, you very likely got a solid-state drive (SSD) as the primary boot drive. Bulkier gaming laptops have moved to SSD boot drives, too, while only a subset of budget machines still favor hard disk drives (HDDs). The boot drives in prebuilt desktop PCs are mostly SSDs now, too, except in the cheapest models. In some cases, a desktop comes with both, with the SSD as the boot drive and the HDD as a bigger-capacity storage supplement.
If you have to pick just one, though, how do you choose? Let’s get into the differences between SSDs and HDDs, and walk you through the advantages and disadvantages of each to help you decide.
HDD and SSD Explained
The traditional spinning hard drive is the basic non-volatile storage on a computer. That is, information on it doesn’t «go away» when you turn off the system, unlike data stored in RAM. A hard drive is essentially a metal platter with a magnetic coating that stores your data, whether weather reports from the last century, a high-definition copy of the original Star Wars trilogy, or your digital music collection. A read/write head on an arm (or a set of them) accesses the data while the platters are spinning.
An SSD performs the same basic function as a hard drive, but data is instead stored on interconnected flash-memory chips that retain the data even when there’s no power flowing through them. These flash chips (often dubbed «NAND») are of a different type than the kind used in USB thumb drives, and are typically faster and more reliable. SSDs are consequently more expensive than USB thumb drives of the same capacities. (See our deep-dive guide to SSD jargon.)
Like thumb drives, though, SSDs are often much smaller than HDDs and therefore offer manufacturers more flexibility in designing a PC. While some can install in traditional 2.5-inch or 3.5-inch hard drive bays, other models can be installed in a PCI Express expansion slot or even be mounted directly on the motherboard, a configuration that’s now common in late-model systems. (These board-mounted SSDs use a form factor known as M.2. See our picks for the best M.2 SSDs and get much more info on these multifaceted types of SSDs.)
(Credit: Zlata Ivleva)
Note: We’ll be talking primarily about internal drives in this story, but almost everything applies to external drives as well. External drives come in both large desktop and compact portable form factors, and SSDs are gradually becoming a larger part of the external-drive market.
A History of HDDs and SSDs
Hard drive technology is relatively ancient (in terms of computer history, anyway). There are well-known photos (Opens in a new window) of the IBM 650 RAMAC hard drive (Opens in a new window) from 1956 that used 50 24-inch-wide platters to hold a whopping 3.75MB of storage space. This, of course, is the size of an average 128Kbps MP3 file today, stored in the physical space that could hold two commercial refrigerators. The RAMAC 350 was limited to government and industrial uses, and it was obsolete by 1969. How far we’ve come!
The PC hard drive form factor standardized at 5.25 inches in the early 1980s, with the now-familiar 3.5-inch desktop-class and 2.5-inch notebook-class drives coming soon thereafter. The internal cable interface has changed over the years from serial to IDE (now frequently called Parallel ATA, or PATA) to SCSI to Serial ATA (SATA). But each essentially does the same thing: connect the hard drive to the PC’s motherboard so your data can be shuttled to and fro.
Most 2.5- and 3.5-inch drives use SATA interfaces (at least on consumer computers), but many high-speed internal SSDs now use the faster PCI Express interface instead. Capacities have grown from multiple megabytes to multiple terabytes, more than a million-fold increase. As for hard drives, current 3.5-inch hard drives are now available in capacities exceeding 10TB.
The SSD has a much shorter history, though its roots do reach several decades into the past. Technologies like bubble memory were briefly popular in the 1970s and 1980s, but the bubbles have long since burst. Current flash memory is the logical extension of the same idea, as it doesn’t require constant power to retain the data you store on it. The first primary drives that we know as SSDs started appearing during the rise of netbooks in the late 2000s. In 2007, the OLPC XO-1 used a 1GB SSD, and the Asus Eee PC 700 series used a 2GB SSD as primary storage. The SSD chips on these laptops were permanently soldered to the motherboard.
(Credit: Western Digital)
As netbooks and other ultraportable laptops became more capable, SSD capacities increased and eventually standardized on the 2.5-inch notebook form factor. This way, you could pop a 2.5-inch hard drive out of your laptop or desktop and replace it easily with an SSD, and manufacturers could design around just one kind of drive bay.
In time, other, more compact SSD form factors emerged, like the mSATA Mini PCIe SSD card and the aforementioned M.2 SSD format (which comes in SATA and PCI Express variants). M.2 has expanded rapidly through the laptop SSD world, and today the SSDs that still use the 2.5-inch form factor are mostly meant for upgrading desktop PCs and older laptops. M.2 is the form factor where modern systems are at.
The Advantages and Disadvantages of SSDs and HDDs
Hard drives are still around in budget and older systems, but SSDs are now the rule in mainstream systems and high-end laptops like the Apple MacBook Pro, which does not offer a hard drive even as a configurable option. Desktop PCs, on the other хэнд, continue to offer HDDs.
That said, both SSDs and hard drives do the same job: They boot your system, and store your applications and personal files. But each type of storage has its own unique traits. How do they differ, and why would you want to get one over the other?
How Expensive Is SSD vs. HDD?
SSDs are more expensive than hard drives in terms of dollar per gigabyte. A 1TB internal 2.5-inch hard drive costs between $40 and $60, but as of this writing, the very cheapest SSDs of the same capacity and form factor start at around $80. That translates into 4 to 6 cents per gigabyte for the hard drive versus 8 cents per gigabyte for the SSD. The differences are more drastic if you look at high-capacity 3.5-inch hard drives. For example, a 12TB 3.5-inch hard drive that sells for around $300 to $350 can push the per-gigabyte cost below 3 cents.
(Credit: Zlata Ivleva)
Since hard drives use older, more established technology, they will likely remain less expensive for the foreseeable future. Though the per-gig price gap is closing between hard drives and low-end SSDs, those extra bucks for the SSD may push your system price over budget.
How Roomy is an SSD vs. an HDD, in Maximum and Common Capacities?
Consumer SSDs are rarely found in capacities greater than 2TB, and those are expensive. You’re more likely to find 500GB to 1TB units as primary drives in systems. While 500GB is considered a «base» hard drive capacity for premium laptops these days, pricing concerns can push that down to 128GB or 256GB for lower-priced SSD-based systems. Users with big media collections or who work in content creation will require even more, with 1TB to 8TB drives available in high-end systems. Basically, the more storage capacity, the more stuff you can keep on your PC. Cloud-based storage may be good for housing files you plan to share among your smartphone, tablet, and PC, but local storage is less expensive, and you have to buy it only once, not subscribe to it.
How Fast Is SSD vs. HDD?
Speed is where SSDs shine. An SSD-equipped PC will boot in far less than a minute, often in just seconds. A hard drive requires time to speed up to operating specs, and it will continue to be slower than an SSD during normal use. A PC or Mac with an SSD boots faster, launches and runs apps faster, and transfers files faster. Whether you’re using your computer for fun, school, or business, the extra speed may be the difference between finishing on time and being late.
(Credit: Zlata Ivleva)
A secondary issue to this: fragmentation. Because of their rotary recording surfaces, hard drives work best with larger files that are laid down in contiguous blocks. That way, the drive head can start and end its read in one continuous motion. When hard drives start to fill up, bits of large files end up scattered around the disk platter, causing the drive to suffer from what’s called «fragmentation.» While read/write algorithms have improved to the point that the effect is minimized, hard drives can still become fragmented to the point of affecting performance. SSDs can’t, however, because the lack of a physical read head means data can be stored anywhere without penalty. This contributes to SSDs’ inherently faster nature.
To put it in number terms? A typical platter-based single hard drive won’t exceed read and write speeds of 250MB per second, whereas a basic SATA-bus SSD will routinely peak at transfer rates twice that. Newer-generation PCI Express-based SSDs, depending on the generation and number of PCI Express lanes supported, can be far faster. They can easily top four times the speed of the fastest platter drives, and the latest PCI Express Gen 4 drives can top out at 3,500MB or even 7,000MB per second, depending on the model. They won’t read and write at those peak speeds all the time, but as you can see, the comparison is not close.
How Durable Is an SSD Last vs. an HDD?
An SSD has no moving parts, so it is more likely to keep your data safe in the event you drop your laptop bag or your system gets shaken while it’s operating. Most hard drives park their read/write heads when the system is off, but when they are working, the heads are flying over the drive platter at a distance of a few nanometers. Besides, even parking brakes have limits. If you’re rough on your equipment, an SSD is recommended.
What Are the SSD and HDD Form Factors?
Because hard drives rely on spinning platters, there is a limit to how small they can be manufactured. Years back, there was an initiative to make smaller 1.8-inch spinning hard drives, but that stalled at about 320GB, and smartphone manufacturers only use flash memory for their primary storage.
(Credit: Zlata Ivleva)
SSDs have no such limitation, so they can continue to shrink as time goes on. SSDs are available in 2.5-inch laptop-drive sizes, but that’s only for convenience in fitting within established drive bays. They are increasingly moving, though, to the M.2 form factor discussed above, and these drives come in 42mm, 60mm, 80mm, and 120mm lengths.