Western Digital WUH721816ALE6L0 16 TB failure rate and reliability

C Grade C: Average

Backblaze logged 10,953 drive-years on the Western Digital WUH721816ALE6L0 from Q1 2023 to Q3 2026, with 2,896 in service at the end of that period. In that time 198 drives failed, an annualised failure rate of 1.81%.

That is 19% higher than the 1.52% average across every drive in the same data, which earns it grade C (average).

Among the 8 graded 16 TB hard drives it ranks 7 of 8 for reliability.

Failures have risen: 2.63% over the latest 8 quarters against 0.82% before. Rising rates often mean a model is ageing.

Failure rate / year: 1.81%
Average, all drives: 1.52%
Drives in use: 2,896
Drive-years: 10,953
Failures: 198
Capacity: 16 TB
Type: HDD
Model number: WUH721816ALE6L0

Failure rate by quarter

Quarter	Drive-days	Failures	Failure rate / year
Q1 2023	240,256	2	0.30%
Q2 2023	239,957	0	0.00%
Q3 2023	245,361	1	0.15%
Q4 2023	271,136	6	0.81%
Q1 2024	277,187	10	1.32%
Q2 2024	270,162	14	1.89%
Q3 2024	278,025	8	1.05%
Q4 2024	277,841	5	0.66%
Q1 2025	271,090	11	1.48%
Q2 2025	272,497	17	2.28%
Q3 2025	274,775	20	2.66%
Q4 2025	274,524	11	1.46%
Q1 2026	267,868	24	3.27%
Q2 2026	268,875	32	4.34%
Q3 2026	268,126	37	5.04%

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

All 16 TB hard drives compared

Grade	Model	Type	Size	Failure rate / year	Drives in use	Drive-years	Failures
A	Seagate ST16000NM002J	HDD	16 TB	0.56%	463	1,607	9
B	Western Digital WUH721816ALE6L4	HDD	16 TB	0.60%	26,751	87,781	529
B	Seagate ST16000NM001G	HDD	16 TB	0.62%	35,594	117,216	725
B	Toshiba MG08ACA16TA	HDD	16 TB	1.03%	38,772	121,800	1,260
B	Toshiba MG08ACA16TE	HDD	16 TB	1.14%	6,170	22,458	257
C	Toshiba MG09ACA16TE	HDD	16 TB	1.71%	1,009	703	12
C	Western Digital WUH721816ALE6L0	HDD	16 TB	1.81%	2,896	10,953	198
D	Toshiba MG08ACA16TEY	HDD	16 TB	2.91%	4,767	19,015	554
–	Seagate ST16000NM000J	HDD	16 TB	2.23%	171	269	6
–	Seagate ST16000NM005G	HDD	16 TB	0.00%	25	94	0
–	Toshiba MG11ACA16TE	HDD	16 TB	0.00%	76	34	0