How to Check SD Card Health in Windows

Unlike SSDs and hard drives which have Self-Monitoring, Analysis and Reporting (SMART) Technology, most SD cards do not have built-in status monitoring and reporting technology. So it’s actually very difficult to check the actual health of the SD card.

Most modern Industry standard SD cards do have such technology. But since they are much more expensive and not available in large quantities in the market, most people go for the commercial grade ones. For this, the only way is to estimate the remaining life by checking the actual usable size of the SD card (after deducting all the bad and corrupt sectors).

While this process doesn’t give a good estimate of the health of the SD card, you can still use it on a Windows system to see if the card is damaged or not.

What Affects SD Card Health?

SD cards have a limited lifespan due to a limit on the possible number of write cycles. However, several other factors could further damage his health.

Finite Write Cycle

The SD card contains an SD microcontroller and a NAND flash chip. The data is actually stored on the NAND chip (which holds multiple flash cells), and the microcontroller is responsible for accessing the blocks in the NAND flash.

NAND chips or flash memory do not work like magnetic memory. If you have written data to a block of flash memory, it is impossible to rewrite the block unless you erase its contents.

Because a NAND chip is a semiconductor device, the erasing and writing processes constantly consume flash cells. So, all cells have a finite number of write cycles. The amount depends on the density of the chip and the technology used.

After crossing this limit, the cell or block becomes dead and cannot be used. And if a lot of blocks are dead, the SD card will lock itself and go into permanent write protection mode.

Most SD microcontrollers perform wear leveling to extend the life of the SD card. This technology uses the number of erases per block to spread the number of deletes evenly across flash memory. However, the write cycle limit remains.

In general, inexpensive SD cards can last up to thousands of write cycles, and expensive ones can last hundreds of thousands. If you use SD cards properly, you can keep using them for 5-10 years depending on where you use them.

Physical Damage and Contact Wear

SD cards use gold-plated contacts as the interface to transfer data between the card and the device. Abrasive materials or frequent insertion and removal can scratch the contacts and wear them out. In such a case, the SD card will not work because it cannot set up a connection with any device.

Also, because contact wear doesn’t affect the NAND chip, it won’t display the NAND chip when you check the health of the SD card. So you need to physically look for it by observing its contacts. The black or dark smudges you may see on your contacts are not scratches, but accumulations of dirt that you can easily clean. You should look for white lines or marks to check for streaks.

In addition to contact wear and tear, physical damage to the plastic or the chips inside will also cause the card to fail.

Other Factors

All semiconductor devices, including SD cards, cannot work properly under hazardous conditions such as high heat, water, etc.

If the card is exposed to such conditions, the chip or its circuitry will suffer internal damage, and the card will fail as a result.

How to Check SD Card Health in Windows?

You can use the CHKDSK tool in Windows to look for any attempts to repair any file system corruption on the SD card.

However, since this process doesn’t actually help you find out the remaining life or the exact health status of the SD card, you will need to use an Original Equipment Manufacturer (OEM) or a third-party app for this purpose.

Disk Check Utility

The only built-in method in Windows to check the health of a storage device, including SD cards, is through the Disk Check Utility, CHKDSK. You can use it to check and fix logical errors in SD card, such as corrupted file system and improper indexing.

Using this tool, you can also search for bad sectors and mark them as unavailable. However, since the wear leveling algorithm on the SD card automatically detects and isolates all bad blocks, you only need to check for logical errors. Checking for physical problems using this tool will actually reduce the number of write cycles remaining.

Go to Run. Type cmd and press Ctrl + Shift + Enter to open Command Prompt as administrator. Type chkdsk /x/f E: while replacing E with the SD Card drive letter and press Enter.

OEM Diagnostic Software

Some SD card manufacturers provide special diagnostic software for their industry standard SD cards. Such SD cards have special components inside, which provide status information, such as the number of bad blocks as well as write cycles for the flash cell.

So, with the right software, you can use these components to check card health. These programs will generally only show remaining endurance or life expectancy. But some also display all bad blocks, number of deletions, etc.

If you have the SD card, check the official Original Equipment Manufacturer (OEM) website and look for the diagnostic software. Some industrial SD cards don’t have proper health monitoring software, so you need to use a third-party app to track their health.

Third Party Diagnostic Software

Most commercial-grade SD cards do not have the diagnostic and reporting components that industrial SD cards have. So it is impossible to accurately check their health.

Several third-party apps, such as H2test or FakeFlashTest are still available which can help you estimate the lifecycle based on the number of bad blocks or the actual size of the card. However, you will not get reliable or accurate results.

How to Keep SD Card Healthy?

Since SD cards can wear out very quickly, it’s a good idea to follow a few practices so that you can extend the life of the card as much as possible.

Avoid defraging the SD card. Unlike magnetic storage disks, Flash memory on SD cards allows quick access to all parts of the storage. So, fragmentation is not an issue on those devices. Defragmentation will only consume unnecessary write or delete cycles. Better to use a file system like FAT32 or exFAT on the SD card. A file system, like NTFS, is a journaling file system that records logs to keep track of any changes made to the drive. Thus, they use faster write cycles. Avoid editing from within the SD card. It’s a good idea to move the files you want to edit to your computer, edit there, then transfer them back. Doing so will minimize the consumption of write cycles on the SD card. Do a quick format—a full format will reduce SD card write cycles. Avoid placing it where it is exposed to direct sunlight or could become hot, such as a car compartment. Be sure to insert the card directly into the camera, laptop or card leader. Use a proper card reader that doesn’t damage the SD card contacts. It is better to eject the SD card before removing it from the computer to prevent logic corruption.