Until recently it was obvious that there was a hard disk in the new computer. Today, especially in laptops, it is possible to choose whether to mount a normal hard disk or a more modern SSD, or solid state drive.
The traditional hard disk, called with the abbreviation HDD, is the fixed memory of a computer, the one that does not empty when you turn off the computer (as RAM does).
Hard drives are essentially metal plates with magnetic coating where data is stored by a head that reads and writes.
An SSD is always a fixed memory like the HDD but it has a different construction: instead of having a magnetic plate that turns, it is a flash memory chip like RAM, however capable of keeping data in memory even if there is no power, i.e. even when the computer is turned off.
The chip can be permanently installed on the system motherboard (as on some small laptops and ultrabooks), on a PCI / PCIe card (on some high-end workstations), or in a box.
These flash memory chips are also different from the flash memory of USB drives, faster and more reliable.
SSDs are therefore more expensive than USB flash drives of the same capacity.
Hard disk technology, to make a little history, is quite old (in terms of computer history).
You can start from the infamous 1956 IBM 350 RAMAC with 24-inch wide platters and 3.75 MB capacity.
Today's drives are 2.5 or 3.5 inches and use SATA interfaces on most PCs and Macs.
Capacities have grown from those few megabytes to more terabytes, an increase of millions of times over 50 years ago.
The SSD is nothing but the evolution of flash memory and we could say that they appeared in 2007 with the Asus EEPC mini netbooks, with 2 or 4 GB capacity.
SSDs and HDDs do the same job of booting the system, loading programs, storing personal files.
There are however many differences, in terms of advantages and disadvantages, in the use of an HDD hard disk or an SSD solid state drive that determine the choice of one or the other.
- Let's start from the Price .
SSDs are very expensive in terms of Euros per GB.
For example, a hard disk of a 2.5-inch TB can cost 50 Euros while an equal SSD, of a Terabyte, could cost 400 Euros.
Hard drives cost less because they are an older and more consolidated technology and because, as we will see, it has lower performance.
So if a 1 TB SSD costs too much, you can buy a 250 GB SSD for 100 euros (on Amazon).
Today the availability of SSDs is higher than that of traditional HDDs which are slowly decreasing on the market.
- Speed
The SSD costs more than a hard disk because it is much faster.
The hard drive has always been the slowest component of a computer, the bottleneck in data processing.
A PC with SSD is capable of booting up in seconds and will continue to be faster than an HDD during normal operation.
A PC or Mac with SSD is able to load programs faster with much better performance.
This marked improvement in performance makes the SSD the perfect drive to install the operating system.
- Fragmentation
HDDs work best with large files that are saved in contiguous blocks on the platter.
In this way, the head can start and end its reading in a single continuous movement.
However, when hard disks start to fill up, large files can be scattered across the disk tray, that is, fragmented.
In SSDs, however, it does not matter where the data is stored since there is no head.
Fragmentation is a concept that does not exist on SSD drives.
- Duration
An SSD has no moving parts, so it is more difficult to break than the HDD which instead always moves (at speeds of hundreds of km / h) and has a high risk of failure.
The life of an SSD is however limited to a certain number of writes (even if TRIM technology has limited this problem today) and there are some precautions for maintaining the SSD and things you should never do on computers with SSD.
- Dimensions
Since hard drives rely on turntables, they cannot be as small as SSDs, which can really be very small.
- Noise : SSDs are silent while, of course, HDDs always make some noise when moving.
In general, therefore, traditional hard drives are preferable, even today, only if there is a need to store a lot of data, in order not to spend too much money.
However, SSDs work better and are faster, stronger, quieter and more durable .
If it weren't for the price and limited capacity issues, the SSD would win the comparison hands down.
It is important to know that it is possible to replace the primary hard disk with an SSD, on the desktop computer and on the laptop.
For example, if you have a desktop PC, you could buy the SSD, transfer Windows and programs to the SSD and leave all the fixed files, images, photos, music, videos and various files on the old hard disk, which it becomes secondary.
If instead you have a laptop with hard disk, you could replace the CD-Rom reader with the SSD unit (work that can be done by the technician or in a computer store).
In another article, the guide to moving Windows to SSD without reinstalling everything
READ ALSO: 8 ways to use an additional disk on your PC
