What Is An SSD?

Recently, I’ve been looking into certain computer components for a potential new system I plan to build. It eventually brought me to the question of if how many SSDs I wanted to use in the computer. It had been a while since I’d had to deal with an SSD, so it drove me to do a little extra research that I wanted to share.

So what exactly is an SSD? An SSD, also known as Solid State Drive, is a data storage device that uses integrated circuits of flash memory. It does not use moving parts or magnets to store data, and is much faster than a standard hard disk drive as a result.

That’s just the tip of the iceberg, however. I wanted to delve a little deeper into solid state drives and explain more about what they are and how they operate.


Important Terms to Know About SSDs

Before we get too into detail about SSDs though, it’s important to take some time to learn a few key terms about these hard drives. Some terminology you may not use in every conversation about SSDs, but it’s important to know them all the same. Especially if you’re planning to buy a new solid state drive, as there might be some things that come up you need to know!

  • HDD – Short for Hard Disk Drive – This is an air tight hard drive with moving mechanical parts it uses to read and write data. It’s still commonly used in computers but slower than a SSD.
  • SSD – Short for Solid State Drive. Unlike a HDD, a SSD contains no moving parts and does not store data magnetically. As a result, it has a much faster read and write time.
  • SATA – Short for Serial Advanced Technology Attachment or SerialATA. SATA is used by most modern hard drives to connect to the motherboard and is much faster than ATA (The previous connection technology before SATA). It also has the benefit of being backwards compatible with ATA.
  • Form Factor – A typical term for computer components that refers to the dimensions and measurements of the component.
  • NAND Flash Memory – This is a memory chip utilized by SSD to read and write data onto the SSD itself. Because flash memory doesn’t use moving parts, this is the reason why SSDs are faster than HDDs.
  • Memory Cells – These are the internal storage blocks inside the flash memory chips that SSDs use to store data.
  • SLC – Short for Single-Level Cell. This is a configuration of memory cells that stores data at a 1 to 1 level. This is the fastest version of memory storage for SSDs. It is also the most expensive version.
  • MLC – Short for Multi-Level Cell. This is a configuration of memory cells that stores data at a 2 to 1 level. This is slower than SLC for memory storage. This is middle of the road in terms of cost for an SSD.
  • TLC – Short for Triple-Level Cell. This is a configuration of memory cells that stores data at a 3 to 1 level. This is the slowest versions of memory storage for SSDs. This is the cheapest version of an SSD.


A Closer Look at SSDs

Solid state drives have been around for decades. Rudimentary technology leading to it being invented all the way back in the 1950s. Solid state memory was even used in NASA to help shield space shuttle computers from the rigors of exiting and entering Earth’s orbit and to shield it from radiation.

If that’s the case, you might ask why they weren’t widely used in personal computers. The answer is actually pretty simple. In the early 90s, hard disk drive (HDD) technology had advanced to a point to provide much higher storage capacity than solid state memory technology at a much lower cost. As the demand for PCs in homes grew, HDDs won out as the more convenient technology to use. If you’d like to learn more about HDDs, I’ve written an article about them here.

That didn’t make SSDs obsolete, however. In recent years, the technology to make SSDs competitive has leapt forward dramatically and as a result, they’ve become a very common component in modern computers.

Note: Solid state drives are not user serviceable. It isn’t advised to ever attempt to repair an SSD yourself should something malfunction. Please allow a professional to perform maintenance on your hard drive!

Solid state drives work with a much more robust memory system than hard disk drives. They use what is called NAND flash memory, though it will typically just be referred to as flash memory. This is the same technology you would see in a flash drive or flash disk. There’s no mechanical or moving parts, but instead, a grid of memory cells hooked up to an electrical grid.

These memory cell grids are typically broken down into three tiers of storage technology:

  • Single-level cell (SLC). These memory cores store one bit of data per cell within the grid. SLC drives write and read data at the fastest speed but at the cost of a higher expense.
  • Multi-level cell (MLC). These memory cores store two bits of data per cell within the grid. MLC drives write and read data at a slower speed than SLC, but are cheaper in cost.
  • Triple-level cell (TLC). These memory cores store three bits of data per cell within the grid. TLC drives write and read data at the slowest speed for an SSD, but as a result are also the cheapest available.

Regardless of which type of SSD you choose to use, the flash memory technology allows for SSDs to far outpace a typical HDD in terms of read and write speeds. Meaning even the slowest SSD will exceed any speed that an HDD can reach.

On top of their increased operating speed, solid state drives also have a much higher resistance to being physically damaged. Their lack of moving parts means nothing will break down over time, and there’s a much lower risk of ruining the hard drive if you were to accidentally drop it.


How Does an SSD Work

Solid state drives work at a much simpler level than a hard disk drive, for instance. Their lack of a need for a spinning hard disk platter and an actuator arm means that the actual way they work is rather tame.

Like an HDD, they communicate with the CPU and RAM. When you send an instruction to the CPU, it will pull information from the RAM, which in turn has been pulling information from the hard drive. SSDs are able to increase the pace at which this cycle is done and as a result, you’ll experience a much more responsive computer.

SSDs have data sent to them via a SATA cable. The information is then sent through the SSD controller unit. This controller unit’s job is to decide where to store data in the memory cells. These cells operate smoother when not completely filled or constantly used to write, delete, and rewrite data.

The controller unit’s job is to ensure that the data you’re storing on the SSD is spread out and no cell is overused too frequently. As a result, the SSD will last longer and you’ll notice very little slow down in its speed even after many years of use.

Advantages and Disadvantages of an SSD

In the modern world of PCs, solid state drives are becoming more powerful and more common. However, that doesn’t make them perfect. There are clear advantages and disadvantages of using SSDs in your computer, and below I’ll give you a breakdown of what you need to keep in consideration.


  • Low power demands – Compared to HDDs, SSDs consume much less power in your PC. On average, they use around 2 watts of energy, while an HDD might use 20 or even 30 watts.
  • No moving parts – As mentioned before, SSDs do not use any mechanical parts in them. There’s no spinning platters or moving arms to read or write data. This means that there’s less risk of internal damage from dropping an SSD.
  • Faster data transmission – The big selling point for SSDs. Their speed will never be matched by an HDD because of their flash memory technology being near instantaneous.
  • Quieter than an HDD – Another bonus feature of having no moving parts. SSDs don’t make any noise. No loud whirring noises when you click on a file you need to load.
  • More heat-resistant – This is likely not a feature most people will be concerned with. However, in a computer that runs hotter, an SSD is much more resistant to higher temperatures than an HDD.
  • Lower failure rate – SSDs just flat out last longer than hard disk drives. Everything breaks down over time, but you can be assured your solid state drive will be far more reliable over years of use than their mechanical cousins.


  • More expensive – Per each gigabyte of storage space, solid state drives are flat out more expensive because the technology is more costly to manufacture. On average, you’re going to be looking to pay around a dollar per gigabyte of storage.
  • Less storage – Another downside of the flash memory technology is that it’s much more difficult to get high storage capacities out of SSDs. When you pair this with their more expensive technology, the two issues compile on top of one another. For the foreseeable future, HDDs will be the kings of cost and storage capacity.
  • Bad compatibility with older computers – This is an unfortunate side effect of SSDs being a newer technology. Despite using a SATA connection, SATA has been in use with computers for a long time. Fact is, some older motherboards just can’t communicate well with an SSD despite supporting a SATA connection.

The advantages of an SSD, in my opinion, far outweigh the disadvantages it has. However, when building a new computer, I would always recommend buying both an HDD and an SSD. Solid state drives are amazing at loading applications and running your operating system, but until new technology is invented, an HDD will still be a great option to store the bulk of your files that you don’t use regularly.

Speeding Things Up (Conclusion)

SSDs have a history that was unfortunately overshadowed for a long time by the much cheaper to manufacture hard disk drive. Now that they’ve made a recent breakthrough and have become a more common sight in the world of computers, I hope you’ve benefited from having a better idea of what an SSD is.

If you have any questions or comments, please feel free to leave them below and I will do my best to get back to you directly!


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