Power-on hours (POH) is the length of time, usually in hours, that electrical power is applied to a device.
A part of the
S.M.A.R.T. attributes (originally known as IntelliSafe, before its introduction to the public domain on 12 May 1995, by the computer hardware and software company
Compaq
Compaq Computer Corporation (sometimes abbreviated to CQ prior to a 2007 rebranding) was an American information technology company founded in 1982 that developed, sold, and supported computers and related products and services. Compaq produced ...
),
It is used to predict drive failure, supported by manufacturers such as
Samsung
The Samsung Group (or simply Samsung) ( ko, 삼성 ) is a South Korean multinational manufacturing conglomerate headquartered in Samsung Town, Seoul, South Korea. It comprises numerous affiliated businesses, most of them united under the ...
,
Seagate,
Toshiba
, commonly known as Toshiba and stylized as TOSHIBA, is a Japanese multinational conglomerate corporation headquartered in Minato, Tokyo, Japan. Its diversified products and services include power, industrial and social infrastructure systems, ...
, IBM (
Hitachi
() is a Japanese multinational conglomerate corporation headquartered in Chiyoda, Tokyo, Japan. It is the parent company of the Hitachi Group (''Hitachi Gurūpu'') and had formed part of the Nissan ''zaibatsu'' and later DKB Group and Fuyo G ...
),
Fujitsu
is a Japanese multinational information and communications technology equipment and services corporation, established in 1935 and headquartered in Tokyo. Fujitsu is the world's sixth-largest IT services provider by annual revenue, and the la ...
,
Maxtor
Maxtor was an American computer hard disk drive manufacturer. Founded in 1982, it was the third largest hard disk drive manufacturer in the world before being purchased by Seagate in 2006.
History
Overview
In 1981, three former IBM employ ...
,
Kingston and
Western Digital
Western Digital Corporation (WDC, commonly known as Western Digital or WD) is an American computer drive manufacturer and data storage company, headquartered in San Jose, California. It designs, manufactures and sells data technology produ ...
.
Power-on hours is intended to indicate a remaining lifetime prediction for hard drives and
solid state drive
A solid-state drive (SSD) is a solid-state storage device that uses integrated circuit assemblies to store data Persistence (computer science), persistently, typically using flash memory, and functioning as secondary storage in the Computer ...
s, generally, "the total expected life-time of a hard disk is 5 years" or 43,800 hours of constant use.
Once a drive has surpassed the 43,800 hour mark, it may no longer be classed as in "perfect condition".
Google tested over 100,000 consumer grade serial and parallel ATA hard disks, finding evidence that S.M.A.R.T. attributes like POH played a heavy role in device failures.
References
Survival analysis
Reliability analysis
{{electronics-stub