You install a drive health tool because something felt off, and it hands you a wall of forty SMART attributes with names like "Seek Error Rate" and raw values in the millions. Somewhere in there is the answer to the only question you have: do I need to buy a drive this week or not?
Good news, most of that table is noise for your purposes. A handful of values genuinely predict failure, a few more are famously alarming and completely harmless, and the whole report comes with a catch worth knowing before you trust it. Here is how to read your drive without a computer science degree, and how PC Workman boils it down to a verdict you can act on.
The values that actually matter
Different drive types report health differently, so start by knowing which kind you have.
On an SSD or NVMe drive, two values carry most of the signal. Percentage Used (or Media Wearout Indicator) estimates how much of the flash endurance you have consumed, and it counts up from 0. Available Spare shows the reserve blocks the drive keeps to replace worn ones, and it counts down from 100 percent. Spare dropping toward its threshold is the serious one. Also worth a glance: any Critical Warning flag, and Media or Data Integrity Errors, which should stay at zero.
On a mechanical hard drive, the classics still hold. Reallocated Sectors Count counts sectors the drive gave up on and replaced from spare. Current Pending Sector Count counts sectors it cannot read reliably and has not yet reassigned. Uncorrectable Sector Count counts the ones it failed on outright. All three should be zero. Any of them rising, especially over weeks, is the clearest software warning a hard drive gives you.
SSD wear, and why it worries people more than it should
Every SSD ships with an endurance rating, usually expressed as TBW (terabytes written). A typical consumer 1 TB drive is rated somewhere in the hundreds of TBW. That number sounds finite and frightening until you compare it with how much you actually write.
A normal desktop user writes a few terabytes a year. Even a heavy one, with games installed and removed constantly and large video files moving around, rarely gets close to the rating inside the drive's practical lifetime. Percentage Used climbing by a couple of points a year is completely ordinary. If yours is at 4 percent after two years, you are on pace to replace that machine long before the flash gives out.
Wear is worth watching, not worrying about, and it is one of those numbers where the trend across months tells you far more than today's reading, exactly like reading a voltage rail over time rather than panicking at one sample.
The symptoms that beat any number
Sometimes the drive tells you before SMART does. Treat these as urgent regardless of what a health tool says:
- Files or folders that vanish, or come back corrupted.
- The drive turns read-only. Some SSDs do this deliberately at end of life to protect what is still on them. It is a final courtesy, not a glitch.
- Freezes when reading a specific folder, while the rest of the system is fine. Often paired with a disk that pins at 100% with terrible response times, which our guide on what 100% disk usage actually means covers.
- The drive disappears from BIOS or Explorer, then reappears after a reboot.
- Clicking or beeping from a mechanical drive. Power it down and recover the data, do not run tests on it.
- Disk errors in Event Viewer, especially repeated ones from the same drive.
The catch nobody mentions
So the practical rule: if the numbers turn, act early and calmly. Copy your data off first, then decide about replacing. Do not run long stress tests on a drive you suspect, because the test is itself the load that finishes it off.
How PC Workman reports it
The gap between a forty-row SMART table and "should I be worried" is where most people give up. PC Workman reads the values that matter for your specific drive type and states the verdict in plain language first, with the readings underneath:
And when something does turn, the honest version says what it can and cannot know: which value moved, over what period, and that a passing check is never a substitute for a backup. That is the same boundary we hold everywhere in the app, including the five-minute health check: report the evidence, name the trend, never fake certainty.
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