SSD defect rate was traced for 5 years.

In the operating system booting environment, the results of the tracking survey that SSDs are more stable compared to HDD (HDD).

Back blaze, a cloud service company in the US, compared the average failure of the operating system boot SSD and HDD from the fourth quarter of 2018 to the second quarter of 2018. Is 3.55%.

This is due to the characteristics of SSDs with no physical operating parts. However, SSDs are restricted from NAND flash memory and are limited to the total writing capacity (TBW) and are sensitive to electrical shocks, so important data should be backed up.

■ Back Blaze, more than 2,000 SSD tracking results release

Back Blaze is a North American cloud service company that operates HDDs (HDDs) of various storage manufacturers such as Western Digital, Seagate and Toshiba. Every year, the defect rate of HDDs for each manufacturer and capacity, which is released by the company, is often a reference for consumers considering the purchase of storage devices.

Since the fourth quarter of 2018, the company has used SSDs as a drive for the operating system for stories. If the newly introduced storage server, as well as the HDD for booting of the existing storage server, is replaced with SSD.

As a result, as of the end of June, 2,558 SSDs are in operation in the storage server operated by the company.

■ SSD defect rate when operating for 5 years, 1/3 of HDD

According to the data that the company has compiled from 2018 to the second quarter of this year, the average HDD's failure rate remains in 1%until the fourth year of introduction. In the seventh year of introduction, it exceeds 6.26%and the ratio is also in the order of the net.

However, SSDs are less than 1% until the third year of introduction. The average breakdown rate of the fifth year of introduction fell to 0.92%, rather than HDD.

Back Blaze explained, In an environment used as a drive for the operating system boot, SSD is more reliable than HDD. He added, With the end of the life of the SSD, the defect rate may increase at a certain point of view, and we will check the SSD's self-diagnostic data for the next few months and investigate how it is related to the defects.

■ Platters and heads such as driving parts, etc.

In the HDD, the discs containing the data works with 5,400 to 7,200 times per minute. The head that approaches the platter and reads the data also works with a motor. Both parts are more likely to fail over time due to external shocks or bad motors.

SSDs, on the other hand, all components such as controller chips, DRAM, and NAND flash memory are electronically operating, so there is no physical failure factor. Except for the initial defects that may occur immediately after the purchase, it can work for a relatively long period of time compared to HDD.

In the average failure rate presented by the back blaze, the failure rate of the SSD is less than 1%.

■ Be careful to the 'total writing capacity' that determines the lifetime of SSD

However, SSDs are not always a safe storage device. This is because the stability of the interior cell inside the NAND flash memory that contains data falls over time.

All SSD manufacturers have a TBW (total writing capacity), the maximum capacity that can be recorded on SSDs. The latest products can record more than 400 TB for 3 years or 5 years, and Samsung Electronics' 990 Pro, which is recently released, allows the record to 600 TB based on 1 TB.

Currently, it is not easy for a general consumer to pass the TBW set by the manufacturer after purchasing SSD. However, if you copy high-resolution photos and videos to SSD from time to time for editing, it is easy to turn over the specified TBW if you use SSD as a cache use of NAS (network storage device).

Even if the TBW is over, it may be possible to record a certain period of time, but the writing speed is significantly lower than the early operation. At some point, he enters a time limit that cannot be recorded at all. If you often copy large amounts of data to SSD, you need to check SSD status with manufacturer-provided software or crystaldiskinfo.

■ Data recovery is almost impossible in case of failure... The important file must back up

The SSD stores data in multiple places to complement the writing speed of slower NAND flash memory and increase its lifespan than DRAM. For this reason, it is almost impossible to recover when an electrical impact is caused by poor power supply or lightning strikes.

HDD, on the other hand, is preserved as it is even if the controller substrate on the back of the product is broken. If you replace it with a substrate with the same components as a broken controller substrate and a substrate equipped with the same firmware, the likelihood of recovering data is also increased.

Therefore, even if the SSD's TBW is a stable level compared to manufacturer standards, it is preferable to regularly back up important photos, documents, and emails to cloud storage, USB flash memory, USB external HDD, and NAS.