# 2021 hard disk failure rate statistical report

3 min read## 2021 hard disk failure rate statistical report

2021 hard disk failure rate statistical report, Seagate 6TB is still durable, 14TB version needs lightning protection

Cloud storage provider Backblaze recently released its latest hard drive failure rates (AFR) report, although the results cannot directly explain all the problems, they still have high reference value.

2021 hard disk failure rate statistical report, Seagate 6TB is still durable, 14TB version needs lightning protection

Last year, they counted a total of 202,759 mechanical hard drives .Seagate,Toshiba, HGST and WDC hard drives of various capacities and age.

The latest report shows that the failure rate for all hard drives has risen from 0.93% in 2020 to 1.01% in 2021, but is well below the 1.83% reported in 2019.

Their analysis pointed out that the decline in failure rate is because new hard drives with larger capacity are more durable. At present, the proportion of large-capacity hard drives has reached 69%.

Backblaze praised some solid hard drives, and the 6TB Seagate ST6000DX000 performed well with a failure rate of just 0.11% and an average continuous lifespan of 80.4 months.

However, the most unreliable hard drives are also from Seagate, such as the 14 TB ST14000NM0138.

The failure rate in the fourth quarter of last year alone was as high as 4.66%. Although lower than the 6.29% in the third quarter of 2021, the failure rate is still too high.

Other details will not be discussed here, as follows:

*Annualized failure rate*

*From Wikipedia, the free encyclopedia*

*Annualized failure rate (AFR) gives the estimated probability that a device or component will fail during a full year of use. It is a relation between the mean time between failure (MTBF) and the hours that a number of devices are run per year. AFR is estimated from a sample of like components—AFR and MTBF as given by vendors are population statistics that can not predict the behaviour of an individual unit.[1]*

*Hard disk drives*

*For example, AFR is used to characterize the reliability of hard disk drives.*

*The relationship between AFR and MTBF (in hours) is:[1]*

*This equation assumes that the device or component is powered on for the full 8766 hours of a year, and gives the estimated fraction of an original sample of devices or components that will fail in one year, or, equivalently, 1 − AFR is the fraction of devices or components that will show no failures over a year. It is based on an exponential failure distribution (see failure rate for a full derivation). Note: Some manufacturers count a year as 8760 hours.[2]*

*This ratio can be approximated by, assuming a small AFR,*

*For example, a common specification for PATA and SATA drives may be an MTBF of 300,000 hours, giving an approximate theoretical 2.92% annualized failure rate i.e. a 2.92% chance that a given drive will fail during a year of use.*

*The AFR for a drive is derived from time-to-fail data from a reliability-demonstration test (RDT).[3]*

*AFR will increase towards and beyond the end of the service life of a device or component. Google’s 2007 study found, based on a large field sample of drives, that actual AFRs for individual drives ranged from 1.7% for first year drives to over 8.6% for three-year-old drives.[4] A CMU 2007 study showed an estimated 3% mean AFR over 1–5 years based on replacement logs for a large sample of drives.[5]*