HGST top for hard drive reliability after 1 billion hours of testing

Some hard disks are more reliable than others, and a new report has cast further light on which drives are less likely to fail.

Backblaze produces regular reports on hard disk reliability and the latest one for Q1 2016 was conducted using over 61,000 HDDs in data centers, with no less than a billion hours of operation in total between them.

The good news is that in the big picture, across all hard drives surveyed, failures decreased, and in fact the recorded annual failure rate of 1.84% is the lowest quarterly number that Backblaze has ever seen. In other words, hard disks are getting more reliable generally speaking.

As to which is the most reliable brand, once again the lowest failure rate was achieved by HGST with 1.03% across 22,731 HDDs (i.e. one in a hundred drives failed in the year running up to Q1 2016).

The next best overall average was Toshiba on 3.06%, although this was based on a very small amount of drives, just 238 of them. Seagate had a failure rate of 3.48%, but that was over a far greater sample of 36,863 drives.

Western Digital brought up the rear with a failure rate of 6.55%. Again, that was over a smaller sample size of 1,691 hard disks. Backblaze says it would buy more Toshiba and Western Digital HDDs, but it simply can't source them in sufficient quantities to make cost-effective purchases.

Seagate back in the game

So without any shadow of a doubt, HGST is the most reliable hard drive vendor at least according to these statistics. While HGST's failure rate remained the same as seen the previous year, though, Seagate saw the biggest improvement with a huge drop from a worrying 10.68% failure rate to the current figure of 3.48%.

The majority of the drives Backblaze uses across all vendors are 4TB affairs – these represent 58% of the company's HDDs in fact – and their annualized failure rate is 2.12%.

Two individual hard drives stood out because they're being run in considerable quantities and they experienced a 0% failure rate in Q1; in other words not a single disk failed. These were an HGST 4TB model (HMS5C4040BLE640) and a Seagate 6TB disk (ST6000DX000).