SDHC (Secure Digital High Capacity) cards are a type of SD card that was introduced in 2006 as an update to standard SD cards. SDHC cards have a capacity of 4GB to 32GB, compared to standard SD cards which top out at 2GB. When SDHC was first introduced, the cards were required to be formatted with the FAT32 file system. However, over time the specification has evolved and modern SDHC cards can use other file systems as well. In this article, we’ll take a closer look at whether SDHC cards are still FAT32 by default, and some of the factors that determine which file system is used.
The History of SDHC and FAT32
When SDHC was first defined in version 2.0 of the SD specification in 2006, the cards were required to be pre-formatted with the FAT32 file system. At the time, FAT32 was the only file system that supported the higher capacities offered by SDHC cards. Standard SD cards used FAT16 or FAT12 instead.
Requiring SDHC cards to be FAT32 ensured compatibility with existing SD hosts and devices. It allowed SDHC cards to be immediately usable in products that supported the SD standard, even if they didn’t specifically support SDHC yet. Formatting the cards with FAT32 out of the box removed the need for users to reformat high capacity cards themselves.
In later versions of the specification, such as v3.0 introduced in 2009, the FAT32 formatting requirement was removed. Cards were still recommended to be pre-formatted with FAT32 for maximum compatibility, but it was no longer required. This gave SDHC card manufacturers more flexibility to choose whichever file system they felt was most appropriate for their cards.
SDHC Cards Today
Nowadays, most newly manufactured SDHC cards still tend to come pre-formatted with FAT32 out of the box. There are a few reasons for this:
- FAT32 is still the most compatible file system for SDHC cards across different devices and operating systems.
- FAT32 supports memory cards up to 32GB, which is the maximum capacity for SDHC per the specification.
- Many SD devices and hosts might still only officially support FAT32-formatted SDHC cards.
However, it’s becoming increasingly common for SDHC cards to be sold pre-formatted with other file systems like exFAT or NTFS instead. This is happening for a few reasons:
Larger Capacity Cards
Some manufacturers now make SDHC-compatible cards with capacities larger than 32GB. These cards don’t fully meet the SDHC specification, but work similarly in most devices. Since FAT32 only supports up to 32GB, these larger SDHC-type cards are formatted with exFAT, NTFS, or other file systems instead.
Operating System Support
Modern operating systems like Windows 10 and macOS High Sierra have full support for exFAT and NTFS. So formatting SDHC cards this way allows them to be immediately usable in the most common consumer devices without needing to reformat.
Performance
Some benchmarks have shown advantages to using exFAT instead of FAT32 on high capacity memory cards in terms of transfer speeds and other performance metrics. So some manufacturers choose to format with exFAT to provide a better user experience.
Compatibility Improvements
Devices and operating systems are much more compatible with non-FAT32 file systems on SDHC cards compared to the early days. Many devices that officially only claim to support FAT32 may now work fine with exFAT or even NTFS in practice.
SDHC Card File System Summary
To summarize the key points on SDHC card file systems:
- SDHC was originally required to be FAT32, but this is no longer the case.
- Most SDHC cards still ship pre-formatted as FAT32 for maximum compatibility.
- Some SDHC cards now come as exFAT or NTFS for larger capacities, performance, and modern OS support.
- Reformatting may be required if your device only supports FAT32 SDHC cards.
In practice, nearly all SDHC hosts and devices still support FAT32-formatted cards. But exFAT and NTFS have become increasingly common and usable as well in modern equipment. Unless you have an older device with known FAT32-only support, SDHC cards formatted as any of these file systems will likely work fine.
Why FAT32 was Required Initially
When the SDHC specification was introduced, requiring cards to be pre-formatted with FAT32 made sense for several reasons:
Maximum File Size
FAT32 allows files up to 4GB in size, which was necessary to support the larger capacities of SDHC cards. Other common file systems at the time had lower file size limits:
- FAT16 – Max file size 2GB
- FAT12 – Max file size 32MB
So only FAT32 would allow making full use of the 4-32GB capacities offered by SDHC cards when they were introduced.
Compatibility
FAT32 was nearly universally supported at the time across DSLR cameras, media players, phones, computers, and other devices. Requiring it ensured SDHC cards would work immediately in the broadest range of equipment without issues.
No Effort Required
Having cards pre-formatted with FAT32 meant users didn’t have to figure out how to format cards themselves to make them work. Inserting an SDHC card would just work, which was important for mainstream usability.
Performance
While not the fastest file system even then, FAT32 provided reasonably good performance across the board. And it was a known quantity for device manufacturers to optimize their products for. Alternative choices may have been less tuned at the time of SDHC’s launch.
Why FAT32 is no Longer Required
A few key factors led to FAT32 no longer being required for SDHC cards:
Operating System Support
Modern operating systems gained support for additional file systems like exFAT and NTFS on memory cards, making them more flexible choices.
Larger Capacity Cards
Some SDHC-type cards now exceed 32GB, the maximum capacity for FAT32. So file systems like exFAT are required for support.
Performance Differences
It became clear in some usage cases that exFAT and NTFS could provide performance benefits over FAT32.
Interoperability Testing
Better testing and development of SDHC interoperability meant devices could support alternative file systems more smoothly.
Complexity
Allowing flexibility in file system format avoided imposing complexity on SDHC cards and device implementations.
Overall the maturation of SDHC, more capable hosts, and strong test and certification procedures made requiring FAT32 unnecessary.
Common File Systems for SDHC Cards
Here is an overview of the most commonly used file systems for SDHC cards:
FAT32
- Max volume size 32GB
- Max file size 4GB
- Compatible with all SDHC devices
- moderate performance
exFAT
- Max volume size 32TB
- Max file size 16EB
- Good performance for large files
- Supported by most modern devices
NTFS
- Max volume size 32TB
- Max file size 16TB
- Good performance on Windows hosts
- Limited compatibility outside of Windows
As you can see, each file system has its strengths that make it suitable for SDHC cards in some situations. But FAT32 offers the broadest device compatibility in most cases.
exFAT vs FAT32
Comparing exFAT against FAT32 in more detail:
Compatibility
FAT32 is essentially universally supported, while exFAT has good but not full support across SDHC devices.
Max Volume Size
exFAT goes up to 32TB, vs 32GB for FAT32. This allows exFAT to support SDXC and larger capacity cards.
Max File Size
exFAT allows much larger individual files – up to 16EB vs 4GB in FAT32.
Performance
exFAT generally has better performance with large files and large overall capacity cards.
File System Structures
exFAT uses simpler structures compared to FAT32, which enables some of its performance gains.
In summary, exFAT builds on FAT32’s broad compatibility while expanding capacity limits and boosting some performance areas.
Reformatting an SDHC Card
If you need to reformat an SDHC card to a different file system for any reason, here are some tips:
Backup First
Always copy off any data on the card before reformatting to avoid permanent data loss.
Use GUI Tools
Use a graphical utility like Windows Explorer or Disk Utility on Mac instead of command line for simplicity.
Choose Allocation Unit Size
Match the allocation unit size to the card’s capacity for optimal performance.
Quick Format
A quick or fast format is fine in most cases for SDHC cards.
Check filesystem
Verify the reformatting completed and the card shows the new desired file system.
Frequently Asked Questions
Are all SDHC cards FAT32?
No, while many SDHC cards still come pre-formatted as FAT32, some are formatted with exFAT or NTFS instead. FAT32 is no longer required by the SDHC specification.
Do SDHC cards have to be FAT32 for digital cameras?
Most dedicated digital cameras are still compatible with FAT32 only. But some newer models may also support exFAT on SDHC cards as well.
Can SDXC cards be FAT32?
No, SDXC cards cannot be FAT32 since FAT32 maxes out at 32GB capacity, and SDXC starts at 64GB.
Is exFAT better than FAT32?
exFAT improves on FAT32 in terms of maximum capacity and file size. It also offers better performance in some cases. But FAT32 still has wider device compatibility.
Does Windows 10 support exFAT SD cards?
Yes, Windows 10 has full built-in support for reading and writing exFAT-formatted SD cards.
Conclusion
While early SDHC cards were required to be FAT32, cards today can come formatted with FAT32, exFAT, NTFS, or other file systems. FAT32 is still the most widely supported format, but exFAT and NTFS have become more common as well. The file system used for an SDHC ultimately depends on the card’s capacity, performance characteristics, and manufacturer preferences. Most devices support FAT32 SDHC cards at a minimum, but many now also work with cards formatted as exFAT or NTFS too.