Advantages of SSD over hard drives They are wide and well known, especially in the performance section. In fact, changing from an HDD to an SSD is one of the best upgrades you can make to your computer. But do you know how an SSD works internally?

There are many articles we have devoted to SSDs, as new models are launched almost weekly. In addition to the buying guide, which we constantly update, we have therefore offered you articles as a use case to say goodbye to hard drives; how to change hard drive to SSD on laptop; connecting an SSD to a computer while keeping the hard drive, or moving Windows from a hard drive to an SSD without losing data. Today we’re going to go a little further to see how an SSD works internally.

Computers and memory

To understand how SSDs work and why they’re so useful, it’s important to understand how a computer’s memory architecture works and each of its parts: cache, RAM, and mass storage.

The cache It is the innermost storage unit. The electrical paths to the cache are the shortest, making data access almost instantaneous. However, the buffer is very small, so its data is constantly being overwritten.

The FRAME It is an intermediate point. Random access memory where a computer stores data related to actively running programs and processes. RAM access is slightly slower than cache access.

The storage unit It is where all the remaining data that requires persistence is stored, and it stores operating system data, applications, games, configuration files, and any user files, documents, video, or music.

It is worth knowing that there is a big difference in performance between the three. While cache and RAM operate at nanoseconds, a traditional hard drive operates at milliseconds. As a result, the storage system was the main bottleneck for the performance of the entire PC.

It doesn’t matter how fast the other components are. A computer can only load and store data as fast as the hard drive can handle it. And this is where the SSD comes in, much faster, which significantly shortens the charging time programs and processes, making your computer much faster.

How does an SSD work?

Solid state drives, or “solid state drives,” serve the same purpose as a hard drive: to store data and files for long-term use. The difference is that modern SSDs (since 2010) use the type Flash memory (similar to those used in RAM) but unlike them are based on NAND gates which They don’t delete data every time you turn off your computer.

Data on the SSD is preserved even when it is without power. Since these are non-volatile memories, they do not require any type of permanent power supply or batteries to ensure that stored data is not lost, even in the event of a sudden power failure.

If you take apart a typical hard drive, you’ll see a stack of magnetic platters, spinning platters with a readout needle like the one on a vinyl record player. Before the stylus can read or write data, the pads must rotate around the correct location.

The SSD structure is completely changing. They have no mechanical or moving partsusing a system of electrical cells to send and receive data quickly. These grids are divided into sections called “pages” and data is stored on these pages. Pages are grouped into “blocks”.

Main parts of SSD

Why is it necessary to know? Because SSD can only write to empty pages of the block. On hard drives, data can be written to any location at any time, which means that data can be easily overwritten. SSDs cannot directly overwrite data on individual pages. They can only write data to blank pages of the block.

So how do SSDs handle data deletion? When enough pages in a block are marked as unused, the SSD caches all the data in the block, erases it, and then resends the data from memory, leaving the unused pages blank. Erasing the blocks does not mean that the data disappears, as we have seen.

Not all are benefits of SSD

AND SSD completely New It is completely packed with blocks of blank pages. When you receive new data in They are written to the SSD breakneck speed. However, as more and more data is written, blank pages run out and the drive is left with random unused pages scattered across the blocks.

As a result of the above, one of the theoretical disadvantages is that Flash memory can only hold a finite number of writes before the end of its useful life. When using an SSD, The electrical loads in each of your data cells must be reset periodically. Unfortunately, the electrical resistance of each cell increases slightly with each reset, increasing the voltage required to write to that cell. Eventually, the required voltage becomes so high that the particular cell becomes unwritable.

How long does an SSD last?

This does not mean that an SSD will necessarily last less than a hard drive. Although memory blocks on SSDs have a limited number of write operations, the new generation They have greatly improved in reliability. All SSDs contain additional free memory cells so that when others fail, they do not lose capacity and redistribute bad sectors.

Stress tests confirmed this increase in reliability with some series of drives that survived a demanding write test. over 2 petabytes. An enormous amount of data that would take decades for a user in real conditions (with normal use).

For the latest generations of SSDs, manufacturers rely on NAND TLC flash memory, three times the level per cell. This technology increases storage density and lowers costs, but reduces the durability of previous formats such as MLC and especially SLC, Single-Layer Cell, which stores only one bit per cell and which you will no longer see in the consumer market.

Manufacturers offer at least a three-year warranty, and we meet in new generations 5-year warranty on consumer units and up to 10 years on the professional market. At the user level, there is nothing to worry about when it comes to durability, but we wanted you to know a little more about how these solid state drives, which are becoming the standard in the storage market, work.