< The MacPaw How-tos

What is Critical S.M.A.R.T. diagnostics?


Why did you get SMART failing alert

Your Mac’s drive has an early notification system called S.M.A.R.T. (Self-Monitoring Analysis and Reporting Technology). It keeps an eye on your disk to spot issues that can lead to drive failure. If you got a Critical S.M.A.R.T. diagnostics alert from CleanMyMac 3, it means the system has identified one of those issues, so you’d better back up your data before the disk fails.

What is wrong with my drive?

S.M.A.R.T. uses sensor-based methods to detect potential disk problems. The sensors measure various attributes of your drive, and when these attributes go out of the normal range, the S.M.A.R.T. status changes to let you know there’s an issue. Depending on its type and manufacturer, your drive can support different attributes. Here are some of the most common ones.

Internal hard disk temperature.

S.M.A.R.T. monitors hard drive temperature, using an internal sensor. When your drive overheats, the system indicates a problem. If you want to know why that happens and how CleanMyMac can help, check out our post on high disk temperature.

Read error rate.

This is how many errors have occured when your system tried to read data from the HDD. A high read error rate usually means the disk surface or the read/write heads are damaged, which is a critical problem for an HDD.

Wear leveling count.

Wear leveling count is the number of erase cycles an SSD can survive. When it reaches a critical level, S.M.A.R.T notifies you that the SSD can fail soon. Read more about why the lifespans of SSDs are limited and how you can extend them in this post on SSD life.

Why my drive is fail

Can CleanMyMac 3 help to detect potential disk problems?

To fix or replace a failing drive, you’ll have to set up a meeting with a specialist and diagnose the problem. What CleanMyMac can help you with is monitoring disk health and preventing some of the problems. Here’s what you can do to keep your disk in good condition.

  1. Check on your drive’s health in the CleanMyMac 3 Menu and pay attention to CleanMyMac’s health alerts. Besides critical S.M.A.R.T. diagnostics, it can alert you to low SSD life (for solid state drives) and high disk temperature.
  2. To extend the life of your SSD, keep 20% of the disk space free. CleanMyMac will help you release that space by finding large files you don’t use and cleaning out junk.
  3. To keep your drive from overheating, try reducing unnecessary load on your system: disable login items, extensions, and helper applications with CleanMyMac’s Extensions module.

If you’re still using the CleanMyMac 3 trial, keep in mind that its cleaning and maintenance power is limited. To clean up more than 500 MB of junk and use Utilities without restrictions, consider buying  the full version.

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