Hard Drive vs Solid State Drive

You have probably heard the term SSD or Solid State Drive before. So what is it exactly and how does it compare to the regular hard drive?

Hard Disk Drives

If you open up a hard drive, you will see a big, circular and shiny platter. It’s invisible to the human eye, but that platter is divided into millions and millions of small sections, which can be magnetized or demagnetized. Both HDDs and SSDs use bits (0 or 1/off or on) to store information, so a magnetized area represents a 1 and a demagnetized area represents a 0. Since electricity doesn’t change magnetism, the data stays on the drive even after you turn the computer off.

Inside the read/write head, there is a tiny magnet that magnetizes the small areas of the fast rotating platter, therefore writing your documents or images on the platter, bit by bit. Can you imagine how many zeroes and ones just a simple .jpg image contains? Assuming our .jpg picture is rather small, let’s say 300 kilobytes, it would equal about 2,4 million bits. That’s 2,4 million little areas that the hard drive needs to magnetize or demagnetize!

 Alright, I’m finally done raving about the speed of just an average home user computer, let’s move on!

Since the parts of a HDD (the read/write head and the platter) move, they are more prone to breaking. If you drop your laptop or bump it hard while data gets written on the hard drive, the little magnetic head can scratch the surface of the platter and make data unusable. A miniscule piece of dust or dirt can also damage the platter.

A hard drive in writing action

Also, when you are looking for certain data on your device, the hard drive must find the correct data in a whole long list of information. For an example, if you go to a library and want to find an author whose name starts with, let’s say, the letter S, you must go through all the letters before S to figure out the exact location. That takes time, which is important when you want great performance and speed from your computer.  That time seems especially long when starting up a computer, which means the hard drive must start spinning – adding a few extra seconds to start-up time. Just a few seconds isn’t a big deal, right?

Well, with Windows 10, for example, it takes the computer approximately 22 seconds to boot up. With an HDD, it can easily take a whole minute and a half. Opening a medium-sized file takes about 4 seconds with an SSD, but 14 with a hard drive. The seconds start adding up quick. Overall, hard drives often act as bottle necks, slumping down the speed of the computer. I think we all know how frustrating it can be to just wait a minute when you’re in a hurry—when every second seems like an eternity. Oof.

An HDD doing its one job

Solid State Drives

Unlike hard drives, solid state drives do not have physically moving parts.

SSD cells that accommodate the charges (like how the HDD parts get magnetized/demagnetized) are organized in blocks, columns and pages. Since its free of slowly moving parts, that means  every little block in an SSD is accessible in the same amount of time. The future is here!

Instead of spinning the platter and magnetizing little parts of the drive, an SSD actually reads from and writes to something called a NAND flash memory (it’s not as complicated as it sounds, promise!). A NAND consists of small non-volatile blocks – that means it works similarly to a HDD block – the charge gets held inside of the little cells (imagine a prison cell) and stays there even when power is removed.

A sneak peek into the SSD

An SSD is only capable of writing data (and reading it) one row at a time, and they cannot overwrite pages. So, what does that mean to you? When an SSD doesn’t have a completely empty or freshly deleted page to write on, it needs to find a page that has some empty cells, copy that page to the RAM temporarily, then delete the unused or stale cells and copy the data back to the original page without the empty cells.

Since the charge in cells gets changed many times over the course of using SSD, the cells have a finite number of writes. This isn’t something you should be too worried about, since the number isn’t that small. If you write about 200 GB of data (regular drives are either 250 GB or 500 GB) on your computer every single day for a whole year, you might be nearing the end of the SSD’s life. 

Also, sometimes the SSD cannot write fast enough to keep up with the data being sent. In that case, the computer stores the incoming data in a data storage place (DSRAM for the geeks out there), which is volatile (remember, it means that when power is removed from the equation, data is lost). Everything sounds fine and dandy, but if your computer turns off at that exact time your data is stored in the temporary storage place, it could have very bad results. The worst-case scenario would be the loss of important system files that can corrupt the operating system or the entire data on the SSD. To avoid that from happening, the SSD manufacturers usually add a mechanism that powers the SSD until everything gets written on the drive (but not all of them, so look out).

A Solid State Drive doing its job

So the bad news? SSDs tend to be more expensive, they get somewhat slower as they age and they usually have less storage space. There’s only a certain number of rewrites on the SSD, so they are not forever. Even still, on average they last longer than your regular HDD and are faster even after “slowing down”.

The conclusion

Swapping out a HDD with an SSD creates the most noticeable improvement in speed for the end user.

If you can spend the extra money for an SSD and you care about the performance and speed of your computer, we definitely recommend getting one. If you’re more about a lot of storage space and don’t need your computer to be particularly fast, you can stick with the good old hard drive.

PRO can speed up your computer by upgrading to an SSD for a flat rate depending on the size of the drive. Read more here:

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