Seagate ST12000NM0007 12 TB failure rate and reliability

F Grade F: Poor

Backblaze logged 4,021 drive-years on the Seagate ST12000NM0007 from Q1 2023 to Q3 2026, with 931 in service at the end of that period. In that time 317 drives failed, an annualised failure rate of 7.88%.

That is 419% higher than the 1.52% average across every drive in the same data, which earns it grade F (poor).

Among the 7 graded 12 TB hard drives it ranks 7 of 7 for reliability.

Failures have fallen: 6.01% over the latest 8 quarters against 9.70% before.

Failure rate / year: 7.88%
Average, all drives: 1.52%
Drives in use: 931
Drive-years: 4,021
Failures: 317
Capacity: 12 TB
Type: HDD
Model number: ST12000NM0007

Failure rate by quarter

Quarter	Drive-days	Failures	Failure rate / year
Q1 2023	112,607	23	7.46%
Q2 2023	109,092	25	8.36%
Q3 2023	110,115	27	8.95%
Q4 2023	108,242	21	7.08%
Q1 2024	104,068	37	12.98%
Q2 2024	101,292	33	11.89%
Q3 2024	99,271	32	11.77%
Q4 2024	96,322	23	8.72%
Q1 2025	92,483	24	9.47%
Q2 2025	91,801	9	3.58%
Q3 2025	91,835	13	5.17%
Q4 2025	90,539	9	3.63%
Q1 2026	87,389	11	4.59%
Q2 2026	87,496	10	4.17%
Q3 2026	84,955	20	8.59%

Single quarters with few drive-days swing widely; the overall figure above is the dependable one.

All 12 TB hard drives compared

Grade	Model	Type	Size	Failure rate / year	Drives in use	Drive-years	Failures
B	HGST HUH721212ALE600	HDD	12 TB	0.90%	2,590	9,719	87
B	Seagate ST12000NM000J	HDD	12 TB	0.97%	1,067	2,271	22
B	Seagate ST12000NM001G	HDD	12 TB	1.13%	13,006	49,098	553
D	HGST HUH721212ALE604	HDD	12 TB	2.40%	12,885	49,399	1,184
D	Seagate ST12000NM0008	HDD	12 TB	2.78%	17,915	71,422	1,986
F	HGST HUH721212ALN604	HDD	12 TB	4.60%	9,328	37,997	1,747
F	Seagate ST12000NM0007	HDD	12 TB	7.88%	931	4,021	317
–	Seagate ST12000NM003G	HDD	12 TB	0.00%	27	47	0