Current Pending Sector Count: Why It's So Urgent
If your SMART tool shows a non-zero Current Pending Sector Count, pay attention. Of all the common SMART warnings, this is the one that most directly says data on this drive may already be unreadable.
What a pending sector is
SMART attribute 197 (C5 in hex) counts sectors the drive tried to read and couldn’t. They’re “pending” because the drive is waiting to decide what to do with them:
- If the sector is later written successfully, the drive may clear it from the pending list.
- If the write fails or the sector stays unreliable, the drive reallocates it to a spare — and your Reallocated Sectors Count goes up.
Why it’s more urgent than reallocated sectors
A reallocated sector has already been handled — the drive remapped it, and new data goes elsewhere.
A pending sector hasn’t been handled. Whatever data was stored there is currently unreadable. If that sector held part of a photo, a document, or file-system structures, that data is at risk right now. And pending sectors often appear in clusters as a drive’s surface or heads degrade — one becomes ten becomes hundreds.
A related attribute, 198 (C6) – Uncorrectable Sector Count, counts sectors that failed even after retries.
What causes pending sectors
- Media degradation — the magnetic coating weakening in spots.
- Weak or damaged read/write heads — the surface may be fine, but the head can no longer read it reliably.
- Physical shock — a drop while running can create damage that spreads.
- Power loss during a write, which can leave a sector inconsistent (these sometimes clear on rewrite).
What to do
- Copy your irreplaceable files first. Pick what matters and get it off before anything else.
- Don’t run full-surface repair tools.
chkdsk /r, defragmenters, and “bad sector repair” utilities force the drive to read and re-read weak areas repeatedly — exactly what you don’t want. - Don’t let a normal copy hammer bad spots. Standard file copies retry unreadable sectors over and over, stalling and stressing the drive.
How to clone a drive with pending sectors
If you need the whole drive, use a disk-imaging approach designed for failing drives: it reads all the easy, healthy areas first, skips unreadable sectors on the first pass, and returns to the difficult ones only at the end with limited retries. This captures the most data with the least wear.
Professional recovery takes this further with hardware imagers that control read timeouts, retry limits, and head behavior directly — and, when a specific head is failing, can image around it.
When to stop
Power down and seek help if pending sectors are climbing quickly, the drive is slow, clicking, or freezing, or copies keep failing. At that stage, every hour of operation can turn a recoverable drive into an unrecoverable one.
The bottom line
Current Pending Sector Count is the SMART number that says “some of your data can’t be read right now.” Copy your most important files immediately, avoid repair tools, and image the drive gently if you need everything.
If the drive is failing faster than you can copy, our hard drive recovery service images drives with pending and uncorrectable sectors using professional hardware — one flat price, no charge unless we recover your data.