SDHC vs SDXC — Capacity, File System and Host Limits
SDHC and SDXC are capacity tiers in the SD standard, not different card shapes: for TF/MicroSD both use the same 15 × 11 × 1 mm body. SDHC covers over 2 GB to 32 GB and uses FAT32; SDXC covers over 32 GB to 2 TB and uses exFAT. The practical limits are FAT32’s 4 GB single-file cap and, more importantly, the host device — an SDHC-only reader will not read an SDXC card even if you reformat it. Choose the tier by what your device supports and by the file sizes you record, not by assuming a higher tier is "better". WINTEL supplies both tiers across the TF card range; specify the tier and format your device requires.
Two tiers, one physical card
For TF/MicroSD, SDHC and SDXC share the identical small body. The tier is about capacity and default filesystem, not the connector or the shape. This is why a 32 GB and a 256 GB TF card look the same but behave differently in a host device.
Capacity and file-system boundary
| Tier | Capacity range | Default filesystem | Single-file limit |
|---|---|---|---|
| SDHC | >2 GB – 32 GB | FAT32 | 4 GB |
| SDXC | >32 GB – 2 TB | exFAT | ~1 EB |
The host device sets the real limit
A device rated "SDHC only" will generally not read an SDXC card, even if you format it as FAT32 — it often checks the card type, not just the filesystem. A device rated "SDXC" reads both. The decisive source of truth is the device manual, not the card label.
What this means for recording workloads
- 4K, high-bitrate or long continuous recording can produce files over 4 GB → needs exFAT → needs the SDXC tier.
- Low-bitrate logging or short clips fit comfortably on SDHC/FAT32.
- Speed is independent of tier: a Speed Class or Video Speed Class marking, present on both tiers, is what governs sustained write.
Specifying for an OEM device
When integrating a card into a product, confirm the SoC or card reader’s supported tier and filesystem first, then order that tier. Do not assume a larger card is universally compatible — match the host. WINTEL supplies both tiers; state the required tier and format in the RFQ so the delivered batch matches your device.
Not sure which applies to your product?
Send your workload — what writes, how often, at what temperature — and we will propose a configuration with the reasoning. We reply to business enquiries within 1 business day.
Request a quoteFrequently asked questions
Is SDXC faster than SDHC?
Not necessarily. Tier is about capacity and filesystem, not speed. Sustained-write performance is set by the Speed Class / UHS / Video Speed Class markings, which exist on both tiers.
My device says "supports up to 32 GB" — can I use 64 GB?
Probably not reliably; that rating usually means SDHC-only. Use 32 GB or below (SDHC) unless the manual explicitly lists SDXC support.
Can I format an SDXC card to FAT32 for an old device?
You can format it, but an SDHC-only host may still reject it because it checks card type, not just filesystem. Confirm with the device maker before relying on it.
Does WINTEL supply SDHC and SDXC?
Both capacity tiers are available across the TF card range. Specify the tier and format your device requires in the RFQ.
Sources
- SD Association — Capacity (SD/SDHC/SDXC/SDUC)
SDHC spans more than 2GB up to 32GB and uses the FAT32 file system; SDXC spans more than 32GB up to 2TB and uses exFAT. Speed grades cover C2/C4/C6/C10, UHS U1/U3, and Video Speed Class V6/V10/V30/V60/V90.
- SD Association — SD Association Fact Sheet
SDHC tops out at 32GB, SDXC at 2TB, and SDUC at 128TB. The SDA is an open industry standards body founded in 2000 by Panasonic, SanDisk and Toshiba; it does not manufacture or sell products itself.
- Microsoft — Microsoft exFAT technology licensing
exFAT is a Microsoft-patented file system that allows single files larger than 4GB (the FAT32 limit); the SD Association adopted exFAT for high-capacity, high-speed SDXC / SDUC cards.
- Microsoft — Azure RTOS FileX User Guide — exFAT / FAT32
FAT32 caps a single file at 4GB and by default addresses storage media up to 32GB; exFAT allows single files of roughly 1 EB; flash / SD cards above 32GB require exFAT.
External sources explain industry standards (accessed 2026-10-18); they describe the standard, not WINTEL product parameters.