Which Hard Drives Are Most Reliable — Here’s The Result Of Billion-hour Test Data

Before buying a hard disk, every one of us wants to know about the durability and reliability of the hard disk. Ironically, this is the most difficult question to answer and there are reasons behind it.

First, testing of products like a hard drive’s life span, a bulb’s lifespan or an airplane’s engine longevity work on the basis of mathematical modelling which is a kind of probability theory. On top of that, companies are not interested in releasing consumer’s data for their product failure.

So, there is no way we can know about the lifespan of the hard drive. But, you can use Backblaze reliability report for the first quarter of 2016 about the hard drive models and manufacturers.

Here is a table which tells about the hard drives failure rate:

Source: Backblaze

From the list above, you can clearly see that HGST hard drives are comparatively lesser prone to failure than the other manufacturers like WDC, Seagate, or Toshiba.

Here is another graph by Backblaze about the hard drive failure rate:

Source: Backblaze

Upon the query that why Backblaze sourced more of the hard drives from Seagate and HGST — not from other manufacturers, they said that they need to buy hard drives in large numbers like 5,000 to 10,000 at a time.

Bulk buying is done for two reasons. One, to keep the unit cost down and other to give a more reliable result. Like Seagate and HGST, they could not find more of Toshiba and WDC hard drives in the market to give the test report.