Learn about the advantages and disadvantages of Solid State Drives (SSDs ) , a type of internal disk that is much faster than HDDs, traditional hard drives.
Even today, the most common type of disk in home computers is the HDD ( hard disk drive) , also called hard disk , hard disk or, simply, internal hard disk .
The HDD is present by default on most laptops and desktops, and consists of a platter with magnetic coating that rotates as the head reads and writes data.
However, for some years the technological evolution has been leading to the rapid diffusion of another type of hard disk to be used internally (or even as an external disk).
This new drive, much faster than HDD, is called SSD ( Solid State Drive) – also commonly referred to as solid state drive or solid state drive .
In almost all computers (portable or fixed) it is now possible (and accessible to everyone’s pockets) to replace the internal disk with a new SDD disk (or with a new HDD).
In this lesson I’ll explain what an SSD is and what are the advantages and disadvantages of SSDs compared to HDDs .
I hope it will help you better understand what suits you best , if you are considering a possible replacement of your current disk with an SDD or HDD to make your computer faster or more capacious .
What is an SSD?
The acronym SSD stands for Solid State Drive, or solid state drive .
An SSD is a device that uses solid state memory (especially flash memory ) instead of magnetic media like traditional HDDs do.
Both the two types of disk (SSD and HDD) are memory devices that the computer can use for data reading and writing operations .
From this point of view there is no difference: an internal SSD disk performs the same functions as the classic HDD, that is to start the system, start programs, and save and load data.
A computer can in fact use an HDD or SSD to store programs, files necessary for the operation of the operating system, and even personal data.
What is the difference in the operation of SSD and HDD?
I’ll explain it to you in simple words.
The main difference between SSD and HDD is in the way of accessing, reading and writing data .
How Traditional HDDs Work
Traditional HDDs consist mainly of a disk with a magnetic patina and a head (actually there are numerous other parts but I won’t go into detail).
Do you remember the turntable with the cartridge running on the record? The operation of the HDD is similar to the old turntables.
A head supported by a metal arm moves across the disk surface to locate and record data in the form of magnetic tracks on the disk surface.
Meanwhile the disc spins at incredible speeds – typically 5400 RPM or 7200RPM – RPM stands for Revolutions per Minute and indicates the revolutions per minute that the disc performs.
The disk is divided into tracks and sectors and the head physically moves. Even if the head is very fast (its movements are imperceptible to the naked eye at real speed), the time for the head movements affects the access and read / write time of the data .
At the beginning of the video below it will be impossible to see the movement of the head in real time. However, you will only be able to see it when the video is shown to you in slow motion:
How SSD Disks Work
An SSD uses a different technology.
It relies on solid state memory such as Flash memory, based on electrical charges recorded by transistors , instead of classic magnetic hard disks (HDDs).
What most distinguishes the new solid state disks (SSD) are the total absence of mechanical moving parts , and the saving method that takes place precisely through flash memory capable of keeping the stored data even when there is no electricity.
You will hear too much technical details, for which I refer you to the page on solid state disks in Wikipedia , just know that the operation and mechanics of SSD disks are close to USB Flash memories, but their writing and reading speed of data is significantly higher than the keys.
Advantages of SSD disks
The SSDs bring significant benefits compared to traditional HDDs , especially in terms of performance.
Here are the main advantages of SSD disks :
An SSD is 30 to 200 times faster than the classic HDD , on all fronts: computer startup, data access / read / write, file transfer.
A computer with an SSD drive has extremely fast boot times . Regardless of the autostart services and programs, a computer with an SSD disk will boot up in seconds. A computer with an HDD can boot up in no time, but never as fast as with an SSD, and in any case only if the computer is optimized for a fast boot .
Accessing files on an SSD is practically instant and writing and reading are significantly faster than on a hard drive. In fact, an SSD disk has practically instant access to all data, while an HDD has to search for data in the surface of the magnetic platters.
An SSD drive can transfer files extremely fast , while an HDD cannot hold its own even if it reaches 7,200 RPM.
HDD disks work best with large files placed in neighboring blocks. But over time, each HDD disk becomes fragmented – files are split into fragments that are scattered across the entire surface of the disk. If the HDD disk is fragmented , the read / write times increase even more, as the head has to move around the disk in search of data fragments.
SSDs, on the other hand, do not suffer from this problem. It does not matter where the data is stored in the chips, since no mechanical movement and no physical reading of the data is required .
The SSDs have no moving parts – are therefore are much quieter than HDDs . The background noise of an SSD will be practically zero, while the moving head of an HDD or the spinning disk of an HDD – particularly if it is spinning at 7,200 RPM – involve a minimum of noise.
Having no moving parts, SSDs resist better shocks . An SSD is much less likely than an HDD to lose data in the event of a crash. A HDD, on the other hand, could easily lose data, especially if the computer is dropped while it is turned on and the various parts of the disk are in motion.
Weight and size
Solid state drives are made up of Flash memory, similar to USB, and are therefore much smaller and lighter on average than hard drives . Here is the weight of the two disks compared: an SSD weighs 70-80g, while an HDD weighs 725-750g.
The SSD disks use a much lower wattage than HDDs. In fact, an SSD consumes, at the moment of peak load, less than 2W against the 6W of a hard disk.
An SSD therefore extends the battery life (important factor in laptops), decreases the energy load on the system, and therefore brings much less heat to the internal temperature of the computer (important factor for the life of your computer).
Disadvantages of SSDs
SSDs, as you read above, therefore dramatically improve computer performance .
At the moment, being a still emerging technology, SSDs have some disadvantages compared to classic HDDs :
The cost per GB of SSDs is still quite high compared to HDDs .
At the date of this lesson (October 2015), a 500 GB SSD disk is around EUR 300.00, while you can find HDDs of this capacity even for less than EUR 60-80.00.
However, the demand for SSDs is constantly growing, and the costs of SDDs are constantly decreasing, so all market analysts predict that in a few years the prices of SSDs and HDDs will be equivalent, for the same capacity.
Also, some manufacturers are already integrating SSDs into new computers instead of HDDs, so if you’re buying a new computer you may already have an SSD built in.
There are many HDD manufacturers in the market such as Western Digital, Toshiba, Seagate, Samsung, and Hitachi. SSD drives are not that popular yet, so for the moment the choice of SSD is limited to a few brands and a few models .
If you look at an entry level price range , currently the base capacity of a HDD is 500 GB, but it is now common to find new computers with a base capacity of 1 TB.
The basic capacity of an entry level SSD is still low: 128 GB. SSDs with larger capacities still cost considerably more than equivalent HDDs.
If you use a lot of multimedia files (movies, pictures, music) and would need 1 TB or more of space to store your files, the cost of an SDD could still be very excessive. At the moment there are SSDs that go as high as 4TB – but they are extremely expensive.
When considering whether to choose an HDD or SSD , or whether to buy a computer with an SSD or an HDD , consider your needs and the current capabilities (and current limitations) of your computer .
From the comparison between SSD and HDD, SSD disks win in terms of speed (absolutely clear!), Durability and reliability.
The HDD disks are rather successful with regard to price (cost per GB), availability of brands and models and capacities .
If you use the computer for work, or even if you only intend to improve the performance of your computer in an absolutely decisive way, I absolutely recommend that you evaluate the purchase of an SSD .
While the cost per GB is still high compared to traditional HDDs, SSDs are actually extremely efficient and can easily go up to ten times your productivity. Once the SSD is installed, you will feel like you have a new computer!
Of course, you should also evaluate how old your computer is and if there are other software or hardware factors that are impacting your performance (for example, your computer is clogged with junk programs or viruses, or the RAM memory is insufficient for your needs. ), and which could therefore somehow reduce the effectiveness of the new SSD.
If you’re on a budget and don’t need to boost your computer’s performance that much, or you just need extra space, you might just want to consider buying a larger HDD, internal or external – you can easily find 1 TB drives for EUR. 60-80.00.
However, keep in mind that the cost of technology to produce SSDs is falling rapidly, making it easy to foresee a future replacement of traditional hard drives with solid state drives. If you are not in a hurry, then re-evaluate the purchase of an SSD in 6 months or 1 year – and you will see how the prices have dropped pleasantly.