How to tell if your SSD is about to fail

An SSD usually gives warning signs in its own health data before it fails, and Pulse by Zaweba shows you those signs. Watch three figures in its Drive health group: the percentage of rated life used, the available spare compared with its threshold, and the count of media errors. Pulse's drive health alert also fires on its own when health declines or 90 per cent of the drive's rated life has been used.

Nothing can promise to predict every failure, and an SSD can occasionally die suddenly. But most wear out gradually, and the drive keeps count as it goes.

How an SSD wears

The memory chips in an SSD can only be written a certain number of times. The drive spreads writes around to even out the wear and keeps a reserve of spare space to replace parts that wear out. Over the years the spare is used up and the rated endurance is consumed. The drive records all of this in its SMART data, which is what Pulse reads.

Checking the health figures

Open Pulse and go to the Temperatures page (Ctrl+2). In the Drive health group each NVMe drive shows its critical warning flags, available spare and the threshold, percentage of rated life used, media errors, power-on hours and temperature. These are read without administrator rights. SATA and USB drives are read through Pulse's optional sensor helper, which you turn on in Settings > Sensor readings.

Here is how to read the signs. Critical warning flags should be clear; any flag set is the drive saying something is wrong. Available spare should sit well above its threshold; when it nears or drops below, the drive is running out of ways to replace worn areas. Life used climbs slowly; a figure approaching 100 per cent means the drive has done the writing it was rated for. Media errors should be zero; a count that rises means data is not being read or written cleanly.

Power-on hours and temperature fill in the background. A drive that runs very hot for long periods is under more strain, and the hours tell you how old it really is.

Letting Pulse keep watch

Health data is only useful if someone looks at it, and most of us don't. Pulse's drive health alert is on by default. It fires when a drive reports a critical warning, new media errors or reallocated sectors, spare capacity below its threshold, or 90 per cent of rated life used. You get a Windows notification from Pulse's tray icon once, and the alert stays in the log on the Alerts page with its date and time.

Keep Pulse running in the tray and tick "Start Pulse when I sign in" in Settings, and the watch carries on without you remembering to check.

Other warning signs

Not every symptom shows up in the numbers. Files that won't open, copies that stall, or a PC that hangs for a few seconds when saving can all point at a drive in trouble. The Live page in Pulse shows disk read and write per app and the whole PC's disk throughput, which helps you rule out an app simply hammering the drive.

When the signs appear

Back up first. Copy anything you can't replace to another drive or another place before doing anything else. Then plan a replacement rather than waiting to see what happens. Pulse by Zaweba has done its job if it gave you time to do both.