Why exFAT Was Chosen for the SD Card Recording Partition - FORARTfe/hALSAmrec GitHub Wiki

One of the critical components of this our setup is the SD card used for storing recorded audio data. After evaluating several filesystem options, exFAT was selected as the preferred format for the recording partition.

Here's why:

✅ Cross-Platform Compatibility

exFAT is natively supported by Windows, macOS, and most modern Linux distributions (via exfat-fuse or kernel support). This makes it ideal for users who need to transfer recordings between different operating systems without additional drivers or conversion steps.

✅ No 4GB File Size Limit

Unlike FAT32, exFAT supports files larger than 4GB, which is essential for long, high-quality multitrack recordings. This ensures uninterrupted recording sessions without the need to split files or manage multiple segments.

✅ Lightweight and Efficient

Compared to NTFS, exFAT is a lighter filesystem with less overhead, making it more suitable for embedded systems and low-power devices like Raspberry Pi or other SBCs used in hALSAmrec setups. It also avoids the journaling overhead of NTFS, which can reduce wear on SD cards.

✅ Better Performance for Flash Storage

exFAT is optimized for flash memory such as SD cards and USB drives. It offers faster write speeds and lower latency compared to NTFS, especially on lower-end hardware. This is crucial for real-time audio recording where performance and reliability are key.

✅ Simpler Maintenance

exFAT does not require complex permission management or journaling, making it easier to maintain and recover in case of improper shutdowns. This simplicity aligns well with the headless and automated nature of hALSAmrec.

❌ Why Not NTFS or EXT4?

NTFS: While it supports large files and is reliable, it introduces unnecessary overhead and is not optimized for flash storage. Write performance on Linux can also be inconsistent without third-party drivers.
EXT4: Excellent for Linux-only environments, but lacks native support on Windows and macOS, making it less portable for users who want to access recordings on other systems.

Summary

Filesystem	Max File Size	OS Compatibility	Flash Optimization	Journaling
FAT32	4GB	✅ Universal	✅ Yes	❌ No
NTFS	16TB+	✅ Win / ⚠️ Linux/mac	❌ No	✅ Yes
EXT4	1EB	✅ Linux only	✅ Yes	✅ Yes
exFAT	16EB	✅ Universal	✅ Yes	❌ No

By choosing exFAT, the hALSAmrec project ensures maximum compatibility, performance, and reliability for audio recording on SD cards, making it the most practical choice for a wide range of users and devices.