Backside line: A research of Backblaze’s hard-drive fleet discovered that HGST and Western Digital drives had decrease failure charges than Seagate and Toshiba drives after accounting for components equivalent to age, capability, working temperature, and type issue. The outcomes present how uncooked fleetwide failure figures can obscure significant reliability variations when producers’ drives are at totally different levels of their service lives.
The peer-reviewed IEEE research was written by Christoph Siemroth of the College of Essex and Yeomyung Park of Sungkyunkwan College. It reviewed information on 443,156 drives utilized in Backblaze information facilities from 2013 by means of the second quarter of 2025. The pattern lined greater than 1.66 million drive-years.
The researchers discovered that HGST drives failed at about 41% of Seagate’s fee when put next below comparable circumstances. WD drives failed at about 52% of Seagate’s fee. Toshiba drives had a fee equal to 107% of Seagate’s fee.
HGST ranked first within the evaluation, though the model is not bought as a separate new-drive possibility. Western Digital acquired HGST in 2012 and later phased out the model.
The research takes a distinct method from Backblaze’s common quarterly reliability reviews, which evaluate the drives lively within the firm’s storage fleet at a given time. The authors mentioned that may produce uneven comparisons as a result of the fleets are usually not the identical age.
HGST accounted for a lot of new Backblaze installations in 2014. Seagate was the principle provider from 2015 by means of 2020. Toshiba had probably the most new installations in 2023, and WD led in 2024. Because of this, reported failure charges can evaluate previous Seagate and HGST drives with newer Toshiba and WD fashions.
The researchers adjusted their evaluation to account for these variations. Additionally they excluded a number of the bias created when drives depart service earlier than they fail. About 146,943 drives, or 31% of the pattern, had been faraway from Backblaze’s dataset with out a recorded failure. Most had been possible changed as the corporate moved to higher-capacity {hardware}.
Toshiba confirmed the clearest change in failure habits as drives aged. Its month-to-month failure fee rose greater than fourfold after 60 months in service. From 50 to 100 months, Toshiba drives failed at a fee of 5 to 6 per 1,000 drives every month. The opposite three manufacturers usually remained at or under 2.5 failures per 1,000 drives per thirty days over that interval.
Seagate had the very best failure fee amongst newer drives within the research. However its fee didn’t enhance as sharply with age as Toshiba’s did. Backblaze has beforehand reported that many drive failures happen earlier than a drive has been in operation for 3 years.
Working temperature additionally mattered. The research discovered that every 1-degree Celsius enhance in common drive temperature raised the failure fee by 2.1%. A ten-degree Celsius enhance would elevate the speed by about 23% when compounded.
Increased-capacity drives carried out higher within the mannequin. Every extra terabyte of capability was linked to a 3.4% decline in failure charges. The researchers mentioned that could be partly tied to newer drive designs, together with helium-filled enclosures and advances in head manufacturing.
The outcomes don’t essentially apply to exhausting drives utilized in client PCs or house storage programs. Backblaze operates enterprise drives in data-center circumstances, and the dataset doesn’t embody comparable workload information for every producer.
The evaluation can be weighted towards shorter service durations. Solely 0.52% of drives within the research stayed in operation for greater than 10 years. That makes the outcomes extra helpful for evaluating reliability throughout a drive’s early and center years than for estimating its full lifespan.
WD and HGST completed shut collectively within the adjusted rating. The authors mentioned that might mirror know-how sharing after WD acquired HGST. Backblaze’s most up-to-date annual report put the corporate’s general annualized drive failure fee at 1.36% in 2025.
