The failure rate is annualized, so age of drive is also factored into the consideration.

Sort of. If we’re mostly seeing failures during the first year or two and high average age, that means their QC is terrible, but that’s something a consumer can work with by burning in drives. If average age is lower, that means drives are probably failing further into their life, which means a burn-in won’t likely detect the worst of it.

If Seagate were so unreliable, why would Backblaze be using so much of them? They used to use cheap consumer drives in the past, but if you look at the drives they have in service, they’re pretty much all enterprise class drives, so it’s not like they’re abusing customer warranties or anything.

Here’s a survey of IT pros from 2019, which gives Seagate the award for every single category for Enterprise HDDs:

While the top two companies of Enterprise HDDs were close in all categories, Seagate has proven itself a leader by being voted Market for the seventh year in a row; also picking up titles for Price, Performance, Reliability, Innovation, and Service and Support, sweeping the board for a two-year streak. Western Digital came in second for all categories trailed by Toshiba.

Backblaze places Toshiba as first for reliability, whereas this survey put them third.

Why the discrepancy? Idk, but there’s a good chance Backblaze is doing something wonky in their reporting, or they have significantly different environmental factors in their datacenters or something than average. Or maybe they’re not burning in their drives (or counting those as failures) and other IT pros are (and not counting those as failures). Maybe their goal is to reduce demand so they can get the drives cheaper. I really don’t know.

I’m not going to tell you what you should buy. I personally have WD drives in my NAS because I got a decent price for them years ago, but I wouldn’t hesitate to put Seagate drives in there either. Regardless, I’m going to test the drives when I get them.