How to Check SSD Health (Windows, Mac & Linux)

To check SSD health, run CrystalDiskInfo on Windows or smartctl -a /dev/nvme0 on Linux. Both tools read SMART (Self-Monitoring, Analysis and Reporting Technology) data directly from the drive’s firmware, giving you wear percentage, reallocated sector count, power-on hours, and total bytes written. The whole process takes under three minutes.

Most people only think about drive health the day data disappears. That’s the wrong order of operations. A modern SSD logs dozens of internal metrics continuously, and almost every early warning sign is visible weeks before a catastrophic failure. You just have to know where to look.

If your laptop has been acting sluggish lately, you may want to rule out drive degradation before you fix a slow laptop with software tweaks that won’t actually help. And if you’re deciding between drive types, the health picture is very different between SATA and PCIe, which is worth understanding when you compare NVMe vs SSD options.

What SSD Health Actually Measures

SSD health is not a single number pulled from thin air. Every major drive manufacturer programs their firmware to track a set of standardized SMART attributes, each measuring a different aspect of how the drive is aging. The four attributes that matter most are Wear Leveling Count, Reallocated Sectors Count, Total Bytes Written, and Power-On Hours. Tools like CrystalDiskInfo and smartctl read these directly from the drive controller, no disassembly required. Understanding what each attribute represents lets you distinguish a drive that’s aging normally from one that’s heading toward failure, and gives you enough lead time to back up before anything critical is lost.

The four attributes that matter most are:

• Wear Leveling Count (SMART attribute 177 on Samsung drives, 173 on some others): tracks how evenly write cycles have been distributed across NAND cells. A raw value dropping toward zero signals the drive is exhausting its write capacity.
• Reallocated Sectors Count (attribute 5): the number of bad blocks the drive’s controller has moved to a spare area. Any non-zero value warrants attention. Values climbing steadily are a serious warning.
• Total Bytes Written (TBW): a cumulative count of all data ever written to the drive. Each SSD ships with a rated TBW endurance, for example 600 TB on a Samsung 870 EVO 2TB or 360 TB on a Crucial MX500 1TB. Approaching that figure doesn’t mean instant death, but it does mean the NAND cells are thinning.
• Power-On Hours (attribute 9): raw time the drive has been powered up. Most consumer SSDs are rated for 1.5 million hours MTBF (Mean Time Between Failures), though that’s a statistical figure across large populations, not a guarantee for any individual unit.

Some tools report health as a percentage derived from Wear Leveling Count, others use a proprietary formula. CrystalDiskInfo displays a “Health Status” of Good, Caution, or Bad based on threshold crossings defined in the SMART spec. Manufacturer utilities like Samsung Magician add their own scoring, typically 0 to 100. Both approaches are valid but they’re measuring slightly different things, so don’t compare scores across tools without understanding the methodology.

One more concept worth having: P/E cycles (program/erase cycles). Each NAND cell can only be written and erased a finite number of times. TLC NAND (used in most consumer drives sold today) typically handles 1,000 to 3,000 P/E cycles per cell. QLC NAND, common in high-capacity budget drives, runs 100 to 1,000 cycles. This is why a 500 GB TLC drive used as a system drive will outlast a 2 TB QLC drive under the same workload, despite the capacity difference.

How to Check SSD Health on Windows

Windows gives you three routes: a free third-party tool that reads SMART data cleanly, manufacturer-specific software that adds predictive features, and built-in command-line options for when you need a quick answer without installing anything.

CrystalDiskInfo (Recommended)

CrystalDiskInfo is the standard tool for this task on Windows. It’s been actively maintained since 2008, supports NVMe drives via the NVMe SMART command set, and reads all major SMART attributes without requiring a reboot or driver installation. Download the portable version from crystalmark.info, run the executable, and the main window shows every drive in your system with its current health status color-coded at the top.

What to check in CrystalDiskInfo: look at the Health Status field first (Good is green, Caution is yellow, Bad is red). Then scan the raw values for Reallocated Sectors Count and Uncorrectable Sector Count. If either shows anything other than 0, note the current value and check again in a week. A static non-zero value is less alarming than a climbing one.

For NVMe drives specifically, CrystalDiskInfo surfaces attributes that older SATA tools miss, including Available Spare (percentage of spare blocks remaining) and the Percentage Used indicator from the NVMe spec, which maps directly to endurance consumption.

Manufacturer Tools

If you own a Samsung drive, Samsung Magician adds a Drive Health assessment that cross-references SMART data with Samsung’s internal endurance models. It also provides a Benchmark tab and an RAPID mode toggle, though you don’t need either for a health check.

Crucial Storage Executive covers Crucial and Micron drives. It shows Total Bytes Written alongside a visual health gauge and supports firmware updates from the same interface.

WD Dashboard handles Western Digital and SanDisk drives. It displays Drive Life Remaining as a percentage and logs historical SMART data if you leave it running in the background.

These manufacturer tools are worth installing once, running the health check, and uninstalling if you don’t need the other features. They don’t add significant diagnostic value over CrystalDiskInfo for most users, but the TBW-relative health scores are easier to interpret at a glance.

Windows Command Line: wmic and PowerShell

For a fast check without third-party software, open an elevated Command Prompt and run wmic diskdrive get model,status. This returns the drive model and a Status field of OK or Pred Fail. “Pred Fail” means at least one SMART threshold has been crossed. The output is blunt but reliable. The limitation is that wmic reports only pass/fail, not the specific attribute that triggered the warning.

In PowerShell, the Get-PhysicalDisk cmdlet gives slightly richer output: Get-PhysicalDisk | Select FriendlyName, HealthStatus, OperationalStatus. HealthStatus values are Healthy, Warning, or Unhealthy. Again, this is a threshold summary, not granular SMART data. Use it when you need a 10-second sanity check and don’t have CrystalDiskInfo available.

Thermal stress is a separate variable that affects NAND longevity independently of write cycles. If your system runs hot, check how to fix laptop overheating before addressing drive health, because sustained temperatures above 70 degrees Celsius accelerate cell degradation on TLC NAND.

How to Check SSD Health on macOS

Apple provides two built-in options, and neither requires downloading anything.

The fastest route: open System Information (hold Option, click the Apple menu, select System Information), navigate to Storage in the sidebar, select your drive, and look at the S.M.A.R.T. Status field. It shows Verified (healthy) or Failing. This is a binary result drawn from the drive’s firmware, identical in mechanism to the wmic approach on Windows.

For more granular data on Macs running macOS 10.15 or later, open Terminal and run system_profiler SPStorageDataType. On NVMe drives inside recent MacBook models, this surfaces Media Health Description and NAND End of Life, which Apple populates from its custom NVMe firmware. If Media Health Description returns “Caution: SSD Drive may fail soon”, treat that as an immediate backup trigger.

Third-party options on macOS are more limited than on Windows. DriveDx (from Binary Fruit) reads full SMART attribute sets on external USB SSDs and some Thunderbolt drives, but Apple’s NVMe controller on internal M-series drives restricts third-party SMART access at the firmware level. For internal drives on modern Macs, System Information and Terminal are genuinely your best tools.

How to Check SSD Health on Linux with smartctl

Linux gives you the most detailed and transparent health data of any platform, provided you use the right tool. smartctl is part of the smartmontools package, available in every major distribution’s default repository. The smartmontools project has maintained the tool since 2002 and its output format is the de facto standard for SMART parsing across the industry.

Install it with sudo apt install smartmontools on Debian/Ubuntu, or sudo dnf install smartmontools on Fedora/RHEL. For a SATA SSD, run sudo smartctl -a /dev/sda. For an NVMe drive, run sudo smartctl -a /dev/nvme0.

The output includes the full SMART attribute table with raw values, normalized values (scaled 0 to 100 or 0 to 253 depending on attribute), and threshold values set by the manufacturer. When a normalized value drops below its threshold, the drive flags a SMART failure. Raw values are in drive-specific units, so always check the attribute name alongside the number.

Key attributes to read in smartctl output:

• Attribute 5 (Reallocated_Sector_Ct): raw value should be 0
• Attribute 177 (Wear_Leveling_Count): normalized value represents remaining life percentage on Samsung drives
• Attribute 194 (Temperature_Celsius): sustained readings above 70 on consumer TLC drives indicate a thermal problem
• Attribute 231 (SSD_Life_Left) or 232 (Available_Reservd_Space): used on Intel and some Micron drives as a direct endurance indicator

For automated monitoring, smartmontools includes the smartd daemon, which runs periodic tests and can email you when a threshold is crossed. Configure it in /etc/smartd.conf. This is the single most practical thing a Linux user can do for proactive drive health monitoring, and it costs nothing once set up.

SSD Health Tools Compared

Check Your SSD Health in 4 Steps

1. Download and install CrystalDiskInfo (Windows) or install smartmontools via your package manager (Linux). Mac users open System Information from the Apple menu.
2. Open the tool and identify your drive. Multi-drive systems will list each device separately. Select the drive you want to inspect, typically your primary system drive labeled as C: on Windows or /dev/nvme0 on Linux.
3. Read the Health Status and three key attributes: Reallocated Sectors Count, Wear Leveling Count, and Total Bytes Written. Reallocated Sectors should be 0. Wear Leveling Count should be well above its threshold. Compare Total Bytes Written against the rated TBW in your drive’s spec sheet.
4. Set a reminder to re-check in 90 days. A single snapshot is useful; a trend line is definitive. If Reallocated Sectors climbs between checks or Wear Leveling Count drops below 10% of its starting value, start planning a drive replacement and back up your data immediately.

Signs Your SSD Is Failing

SMART data tells most of the story, but your operating system will show behavioral symptoms too. Watch for these patterns:

• Files become corrupted or unreadable without an obvious cause, particularly after a normal shutdown and restart
• The drive disappears from Device Manager or Disk Utility unexpectedly, then reappears on reboot
• Write speeds drop significantly below spec; a drive that benchmarked at 500 MB/s sequential write now delivers 80 MB/s
• The system freezes briefly during file operations but not during CPU-intensive tasks
• Windows reports Error 0x80070070 (disk full errors on a drive with free space) or CHKDSK finds and quarantines bad sectors on a run initiated from the recovery environment
• Boot times increase steadily over weeks with no new software installed, particularly on systems with a single drive handling both OS and storage

If you’re seeing two or more of these symptoms alongside a Caution or Bad status in CrystalDiskInfo, treat the drive as compromised. Not failing tomorrow, necessarily, but unreliable enough that you should not trust it as your only copy of anything important.

What to Do When Health Is Low

A drive reporting low health is not a crisis. It’s a timeline. The practical response is calibrated to where you are on that timeline.

If health is below 20% on Samsung Magician, or Wear Leveling Count has crossed its manufacturer threshold in CrystalDiskInfo, the first action is a full backup to a separate physical drive. Not a cloud sync, which can propagate file corruption. A local backup to a drive you own and can physically verify.

After securing the backup, order a replacement drive. Current pricing for a Samsung 870 EVO 1TB (SATA) runs roughly $70 to $80, while a WD Black SN850X 1TB (NVMe PCIe 4.0) sits around $80 to $100. Both are drop-in replacements for most laptop form factors, either 2.5-inch SATA or M.2 2280.

While the degraded drive is still functional, clone it to the new drive using Samsung Magician’s built-in clone utility or a free tool like Macrium Reflect. Cloning while the drive still passes SMART avoids the more complicated scenario of recovering a partially dead drive. Once the clone is verified bootable, format the old drive and keep it as an offline backup for 30 days before discarding.

If CHKDSK is flagging errors or the drive is intermittently disappearing from the system, skip the clone attempt and restore from your backup onto the new drive instead. Cloning from an actively failing drive risks carrying the corruption across.

Frequently Asked Questions

What is a good SSD health percentage?

A health percentage above 80% is generally considered good for a consumer SSD in regular use. Drives reporting 90% or above still have years of typical workload capacity remaining. Once health drops below 20%, the drive is nearing end of advertised endurance; at that point, back up immediately and begin sourcing a replacement.

How long do SSDs last?

Most consumer SATA and NVMe SSDs last 5 to 10 years in typical desktop or laptop use. The practical limit is usually TBW endurance rather than calendar time. A 1 TB TLC drive rated at 600 TB TBW, used at 30 GB of writes per day, would reach its rated endurance in roughly 54 years, making age a secondary concern for most users.

Does checking SSD health with software cause wear?

No. SMART data is logged passively by the drive’s own controller. Reading those attributes via CrystalDiskInfo, smartctl, or any other monitoring tool is a pure read operation with no writes to the NAND cells. You can check daily without measurable impact on drive lifespan.

Can Windows CHKDSK damage an SSD?

Running CHKDSK in read-only mode (chkdsk C: without the /f or /r flags) does not write to the drive and carries no risk. The /f flag writes corrections to the file system; the /r flag additionally remaps bad sectors. Both are safe on a healthy drive but can accelerate failure on a drive already reporting bad sectors. Run CHKDSK /r on a degraded SSD only after backing up your data.

Is it worth replacing an SSD that still shows Good health?

Not for health reasons. A drive reporting Good status with no SMART threshold violations is performing within spec and does not need replacing. Valid reasons to upgrade include needing more storage capacity, migrating from SATA to NVMe for performance gains, or upgrading to a newer PCIe generation. Health alone is not a reason to replace a functioning drive.

Check Now, Not After the Problem

The tools are free, the process takes three minutes, and the SMART data sitting in your drive right now is either reassuring or actionable. Open CrystalDiskInfo today, note your Reallocated Sectors Count and Total Bytes Written, and put the numbers somewhere you’ll find them in six months. That’s the baseline. Everything useful in drive health monitoring flows from having one.