SD cards have become an essential storage medium for many devices, including digital cameras, smartphones, drones, gaming consoles, and more. However, SD cards can fail over time as they endure repeated read and write cycles. Knowing the health and expected lifespan of your SD card is important to avoid unexpected data loss or device malfunctions. There are several methods to check an SD card’s life expectancy and monitor its condition.
Check Total Host Writes
One way to gauge the remaining life of an SD card is to check its total host writes – the cumulative number of write operations performed by the host device. This gives you a general idea of how much the card has been used. SD cards are often rated for a total write endurance between 10,000 to 100,000 writes before failure.
To check the total host writes on Windows, insert your SD card into your computer. Open the command prompt and use the command:
fsutil volume diskfree C:
Replace C: with the drive letter for your SD card. Look at the Total # of Write Operations value. Compare this to your card’s total rated writes to estimate Used Lifespan %.
On Mac OSX, install and open Disk Utility. Select your SD card and view the info. Look for the Total Write Operations value. Again, compare this to your card’s total rated writes to gauge wear level.
Higher total writes suggest your SD card has undergone more use and may be closer to failure. While not a precise lifespan estimate, this at least informs you if the card has had light or heavy usage history.
Check Lifetime Writes Remaining
To view the SD card’s remaining rated lifespan, you can use tools that analyze the card’s S.M.A.R.T data – a technology built into storage devices to monitor their health.
On Windows, you can use free utilities like H2testw or SD Card Health Inspector to read your SD card’s S.M.A.R.T data, including its remaining rated write cycles before failure. This gives you a more accurate estimate of how much reliable lifespan remains, expressed as a percentage of total rated writes.
For Mac OSX, tools like SD Card Utility can read the S.M.A.R.T data and remaining rated writes of your SD card. Consult your SD card manufacturer’s specs to better understand the complete write endurance rating.
Check Card Health
In addition to checking total writes, it’s also important to examine the current error rate and overall condition of your SD card for signs of failure.
Again, utilities like H2testw and SD Card Health Inspector will analyze your card’s S.M.A.R.T data to report health parameters like:
- Raw Read Error Rate – Higher error rates indicate issues reading data.
- Data Unit Reallocation Count – How many data units needed to be remapped due to read/write errors.
- Write Error Rate – Frequency of errors while writing data.
- Read Failure Rate – Frequency of errors while reading data.
Higher values for these parameters suggest your SD card may be deteriorating. Compare values against thresholds like:
- Raw Read Error Rate – 10-100 good, 100+ marginal
- Reallocation Count – 5-10 good, 10-20 marginal, 20+ failure likely
- Write/Read Error Rate – 100+ indicates issues
SD cards that exceed thresholds may be near end of life and should be replaced.
Perform Manual Tests
You can also manually test your SD card’s health by reading and writing sample files to check for errors.
Use your computer to write a large test file (e.g. 1GB) filled with binary data to your SD card. Then read back the file and use a program like H2testw to verify the integrity of the data. Any reading errors indicate problematic areas on your SD card that may get worse.
Repeat the test over time to determine if error rates increase, signaling a deteriorating card. Try reading and writing files to all areas of the SD card to fully test functionality.
You can also reformat the SD card and retest – cards that develop bad sectors may fail to reformat properly.
Monitor Card Performance
Aside from directly checking health stats, you can indirectly gauge your SD card’s condition by monitoring changes in its performance.
As cards wear out, you may notice:
- Lower read/write speeds – Compare speed benchmarks against when your card was new using a tool like CrystalDiskMark.
- Longer saving times for cameras – Can indicate read/write issues.
- Lagging or freezing of devices – Can signal problems accessing data on failing cards.
- Corrupted files and unexpected unreadable sectors.
If your SD card exhibits deteriorating performance, it’s likely nearing the end of its usable life, even if total writes or health checks appear OK. Backup your data and replace unstable cards.
Monitor Card Health in Devices
Many cameras and devices provide integrated SD card health monitoring:
- Cameras – High-end DSLR and mirrorless cameras often display life statistics like total shots taken, shutter count, remaining rated shutter life.
- Smartphones – Android phones can use the DiskInfo app to read SD card S.M.A.R.T data like total data written.
- Game Consoles – Nintendo Switch reports approximate remaining play sessions based on SD card used capacity.
- Drones – Apps like DJI GO show SD card status like remaining photos/video time.
While device metrics differ, keeping an eye on your SD card health through built-in monitors can provide early warning of issues.
Best Practices
To maximize your SD card’s lifespan and minimize data loss risks, keep these best practices in mind:
- Replace cards that exceed 60-75% of total rated writes – Don’t wait for complete failure.
- Reformat cards every 6-12 months to recondition cells.
- Use high-quality, name brand SD cards from reliable manufacturers.
- Avoid low-cost, counterfeit or unknown brand cards.
- Purchase cards rated for higher write cycles if using in intensive applications like video recording.
- Back up your SD card data regularly in case of failure.
- Avoid exposing cards to extreme heat, moisture, shocks.
- Carefully insert and remove cards to avoid physical wear.
- Store cards properly in protective cases when not in use.
Following best practices will help you reliably utilize SD cards through their full usable lifespans.
SD Card Failure Signs
Watch for these symptoms of SD card end-of-life failure:
- Frequent read/write errors and data corruption.
- Card becoming read-only or unusable.
- Failed reformats or inability to reformat card.
- Visible physical damage like a warped casing.
- Electronics detecting the card but not the data on it.
- Dropping performance and speeds.
- Overheating card.
- Unmounting spontaneously from computer/device.
At the first signs of failure, immediately stop using the SD card to prevent further data loss. Replace damaged cards.
Data Recovery
If your SD card fails before you can retrieve the data, there are recovery options available:
- Software Recovery – Programs like Disk Drill can read failing cards and recover data.
- Professional Recovery – Experts can dismantle cards and directly access memory chips to recover data.
- Factory Recovery – Sandisk and some brands offer a last resort paid data recovery service.
However, SD card data recovery can be expensive, difficult, and not guaranteed. Your best bet is following healthy maintenance and replacement practices.
Conclusion
SD cards are a convenient but fragile storage medium with a finite lifespan. Checking total writes, health stats, error rates, and performance benchmarks provides vital visibility into the condition of your card over time. Watch for failure warning signs and be prepared to replace unstable or deteriorating SD cards. With proper maintenance and monitoring, you can catch cards before they fail and maximize their usable service life.