What are the most reliable hard drives? That's a question any computer user might ask, but when you own and heavily use 27,134 of them, as online backup Relevant Products/Services provider Backblaze does, the answer is critical. In recent blog postings, the company has decided to share its findings from the last three years.

The top two brands used in those 27,000-plus drives are Seagate and Hitachi, with nearly 13,000 each, followed by Western Digital with about 2,800. Toshiba and Samsung are in the mix with a few dozen representatives each. One aspect to keep in mind, of course, is that Backblaze is using these drives more heavily than any single consumer or business Relevant Products/Services would.

In a blog post Tuesday on the Backblaze corporate blog, Principal Engineer Brian Beach said the company buys "the least expensive drives that will work," all of which are consumer grade, with sophisticated software Relevant Products/Services maintaining backups in case of failure. He added that, when a new model is released, they buy some and test them with initial setup tests, a stress test and then a few weeks in production. If it passes those hurdles, the model assumes a position on the buy list, which, when the price is right, triggers a purchase.

'Spend a Bit More'

But, as one might expect, price is not the key factor at that point, since Beach said the company is willing to "spend a bit more" on more reliable drives. Some drives don't work in the Backblaze environment, for various reasons, including the Western Digital Green 3 TB drives and the Seagate LP (for low power) 2 TB drives. The company believes their incompatibility stems from a too-high vibration level in its storage Relevant Products/Services pods, where the drives are housed.

Backblaze said that, "if the price were right, we would be buying nothing but Hitachi drives," because they have been "rock solid," with a low failure rate. The models used include the Hitachi GST Deskstar 7K2000 and 5K3000, and the Deskstar 5K4000 and 7K3000.

The Seagate Barracuda LP 1.5 TB gets praise for having a venerable average age of nearly four years, while larger Seagates in the 2 to 4 TB range are "solid workhorses," but they tend to wear out. The Seagate Barracuda Green 1.5 TB models, however, a warranty replacement for older drives, "are dropping like flies."

Hitachi, Least Trouble

The company said it wishes it had more of the Western Digital Red 3 TB WD30EFRX, although they came out after it already had a number of Seagate 3 TB drives.

In terms of untroubled operation of drives, Hitachi wins hands down, in particular the 3 TB Deskstar 7K3000, with a 0.9 percent failure rate, followed by the Deskstar 5K3000. The brand itself has an average 99.99 percent uptime, followed closely by Seagate at 99.72 and Western Digital at 99.83. Newer purchases are focused on 4 TB drives, notably the Seagate Desktop HDD.15 ST4000DM000 and the Western Digital 3 TB Red WD30EFRX.

Backblaze competes in the consumer-level, cloud Relevant Products/Services-based, low-cost backup market with such services as CrashPlan. But it has also become known for open-sourcing its storage pod design, which it first did in 2009. These self-contained, metal cases with drives inside have had their designs updated by Backblaze several times, which custom-builds them after the company deemed the commercial versions too expensive.