SSD: How Do They Work, And How Long Can They Actually Last?

How much data do we produce? According to the IDC’s report on the ever-growing datasphere, which was released in not-so-far 2018, the total size of the world’s collected data is expected to hit the daunting 175 zettabytes by 2025 — for a compounded annual growth rate of 61 percent. But with surging storage needs across a wide range of industries, from large enterprises to small companies and managed services providers (MSPs), will SSDs we have today be enough to handle all that data? And what options do we actually have these days to cope with objectives like this? Let’s figure out.

SSD & HDD: What’s the Difference?

While remaining the main competing options, the operation of solid-state drive (SSD) and hard disk drive (HDD) use completely different methods and rely upon completely different data storage technologies. To compare the benefits and assess the drawback of each of them, it’s necessary to understand the difference in their mechanisms first.

Hard Disk Drives

The principle of operation of the “spindle and platter” system — the one HDDs are commonly based on — is quite similar to that of a record player. Hard disk drives are made up of a read-and-write head (also known as a needle) meant to read the information, and a platter (or several) coated with magnetic material that stores data in a very orderly pattern of circular concentric paths, or “tracks”. However, unlike in record players, the needle in an HDD doesn’t actually touch the surface of the platter; instead, it hovers a tiny distance above, moving across in search of the desired information. 

Along with that, the platters themselves are powered by the spindle motor that is disposed on the underside of the hard disk and is responsible for spinning the magnetic platters at speeds of around 7,200-15,000 RPM. As you might guess, all these moving parts together constitute an extremely fragile structure that is significantly susceptible to any physical damage, as well as harmful influences of overheating and high humidity.

At the same time, despite the rather high risks of needing HDD data recovery, HDDs are still in great demand for they offer a wide range of storage capacities at a very low cost, which makes them a perfect option for private users and small businesses.

Solid-State Drives

Solid-state drives are called that specifically because they are devoid of moving parts. Compared with traditional hard disk drives, SSDs are considered much more dependable as they rely on flash memory chips — usually NAND flash chips — instead of magnetic media, using semiconductors that alter the electric charges of these arrays, and storing your data in the process. 

Now, NAND itself is made up of what are called floating gate transistors. Unlike the transistor designs applied in DRAM, which need to be refreshed multiple times per second, NAND flash is intended to retain its charge state even when not powered up. And that’s how NAND is a type of non-volatile memory.

With all the above, solid state drives are able to offer businesses a range of benefits, from improved performance to greater durability. However, because SSD technology is so new, many people have questions about its reliability and longevity. No matter if you’re looking to upgrade your computer with a new drive, or willing to invest in SSDs for your MSP or your customers, it’s important to know the ins and outs of SSDs so you can make the most informed decision possible.

SSD Life Expectancy

With solid-state drives being fairly new to the market, manufacturers are yet to figure out how long they can last. To estimate SSD’s lifespan, vendors currently resort to three different metrics: the total number of terabytes written over time (TBW), the drive writes per day (DWPD), and its age — and, depending on which one you use, the answer to the question “How long do SSDs last?” will vary.

For instance, age is a valuable determinate in the performance and longevity of an SSD. The most recent estimates put the age limit for SSDs around 10 years — although the average SSD lifespan is shorter. At the same time, according to the research conducted by Google and the University of Toronto, where SSDs had been tested over a period of many years, it was proven that the age of the SSD was the major factor in predicting it to stop working. Along with that, the study also found that solid state drives were replaced by about 25% less frequently than HDDs.

The total number of terabytes written over time (TBW) is another way to measure SSD’s lifespan. TBW estimates how many successful write cycles you can expect a drive to make over its lifetime. Say, if a manufacturer claims their SSD has a TBW of 150, it will mean the drive can write 150 terabytes of data — and, once that threshold is hit, it’s likely you’ll need to replace it. 

The last of three metrics that vendors can use when predicting the lifespan of the drive is the number of discs written per day (DWPD). DWPD refers to the number of times users can overwrite the amount of available storage on a disk each day. If the SSD has a 200GB capacity and comes with a five-year warranty, for example, users can write 200GB to the drive every day during the warranty period before it fails. After all, when in doubt, you can use an online SSD life calculator to estimate the life of your drive.

Do Solid-State Drives Fail?

Unfortunately, they do: whereas traditional hard drives often go belly up because of mechanical issues, solid-state drives may fail due to the methods used to write data. 

As previously mentioned, SSDs use flash memory cells to store information: while functioning almost like large flash drives, it programs data into these cells by changing their electrical charges. However, once the available memory on the drive is filled, the SSD can only add new information by deleting older data. This process is called a program/erase cycle, or a P/E cycle for short.

With the number of P/E cycles being limited for every device, each of those cycles is gradually degrading the memory of your SSD cells until they eventually become worn down — and once you’ve reached the point, the drive will no longer be usable.

In addition to that, the breakage of the chip controller is another common cause for an SSD to fail. Due to the technology used, recovering data from a failed solid-state drive is a nearly impossible thing to do yourself as it requires replacing a broken controller with a functioning controller chip that is identical to the bad one… And what sounds quite simple is a difficult task in reality.

To regain access to your data, you’ll need to contact a trustworthy data recovery lab. Given that, SalvageData offers you a free examination of your device along with extremely competent help in mastering these challenges and getting lost files successfully recovered.