{"id":108991,"date":"2023-06-15T09:34:15","date_gmt":"2023-06-15T16:34:15","guid":{"rendered":"https:\/\/www.backblaze.com\/blog\/?p=108991"},"modified":"2025-12-11T11:03:15","modified_gmt":"2025-12-11T19:03:15","slug":"making-sense-of-ssd-smart-stats","status":"publish","type":"post","link":"https:\/\/www.backblaze.com\/blog\/making-sense-of-ssd-smart-stats\/","title":{"rendered":"Making Sense of SSD SMART Stats"},"content":{"rendered":"\r\n
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Over the past several years, folks have come to embrace the solid state drive (SSD) as their standard data storage device. It\u2019s gotten to the point where people are breathlessly predicting the imminent death of the venerable hard drive. While we don\u2019t see the demise of the hard drive happening any time soon, SSDs are here to stay<\/a> and we want to share what we know about them. To that end, we\u2019ve previously compared hard drives and SSDs<\/a> as it relates to power, reliability, speed, price, and so on.\u00a0 But, the one area we\u2019ve left primarily unexplored for SSDs is SMART.<\/p>\r\n\r\n\r\n\r\n

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SMART<\/a>\u2014or, more properly, S.M.A.R.T.\u2014stands for Self Monitoring, Analysis, and Reporting Technology. This is a monitoring system built into hard drives and SSDs whose primary function is to detect and report on the state of the drive by populating specific SMART attributes. These include time-in-service and temperature, as well as reliability-based attributes for media condition, operational efficiency, and many more.<\/p>\r\n<\/div>\r\n\r\n\r\n\r\n

Both hard drives and SSDs populate SMART attributes, but given how different these drive types are, the information produced is quite different as well. For example, hard drives have sectors, while SSDs have pages and blocks. Let\u2019s take a look at the common attributes of hard drives and SSDs, and then we\u2019ll dig into the SSD SMART attributes we\u2019ve found useful, interesting, or just weird.<\/p>\r\n\r\n\r\n\r\n

Let\u2019s Get SMARTed<\/strong><\/h2>\r\n\r\n\r\n\r\n

For each SSD model, the drive manufacturer decides which SMART attributes to populate. Attributes are numbered from 1 to 255, with raw and normalized values for each attribute. Some SMART reference material will also list attributes in hexadecimal (HEX), for example, decimal 12 will also be shown as \u201cHEX 0C.\u201d\u00a0\u00a0<\/p>\r\n\r\n\r\n\r\n

At Backblaze, we have over a dozen different SSD models in service, and we pull daily SMART stats from each. To simplify the task at hand for the purposes of this blog post, we chose three SSD models, one each from Seagate, Western Digital, and Crucial, to show the similarities and differences between the models. All three are 250GB SSDs.<\/p>\r\n\r\n\r\n\r\n

To that end, we have created a table of the SMART attributes used by each of those three drive models. You can download a PDF of the table<\/a>, or jump to the end<\/a> of this post to view the table.\u00a0 Things to note about the table:<\/p>\r\n\r\n\r\n\r\n