SD cards
The SD card is EGO1's offline storage.
A card ships with the unit — a Movespeed A1 V30 128 GB, pre-formatted FAT32. It is ready to use: insert it and record. The rest of this page is for buying spares, running several cards per device, or choosing a more robust filesystem than the one the card ships with.
Card choice matters when you do buy your own. The microSD/TF market is full of counterfeit and low-grade cards, and a fake or incompatible card will cause the device to fail to recognize it or to not record at all.
Requirements
| Property | Requirement |
|---|---|
| Format | exFAT, FAT32, or ext4 |
| Capacity | ≤ 128 GB recommended |
| Speed class | At least A1 and V30 (A2 / V60 / V90 are fine) |
| Quality | Genuine card from a reputable seller |
The shipped card meets all four — matching it (A1 / V30, 128 GB, reputable brand) is the safe way to buy spares.
Choosing a card
- Use a card rated at least A1 and V30 — these classes sustain the write speed needed for dual 1080p H.265 streams. Higher classes (A2, V60, V90) are fine.
- A card below that class may be too slow and fail to record even if it mounts.
- Buy from reputable sellers. Counterfeit and low-grade cards are common and may not be recognized, or may drop data mid-recording — verify a new card before relying on it (see below).
Formatting
The card that ships with the device is already FAT32 — you do not need to format it.
For a card you supply yourself, format it as exFAT, FAT32, or ext4 before first use; all three are supported. Use your operating system's disk utility (built-in tools typically offer FAT32 for cards up to 32 GB and exFAT for larger cards), or the SD Association's official SD Card Formatter.
The device identifies the filesystem by trying to mount it, so there is nothing to configure on the device side. A card it cannot mount is left alone rather than reformatted — the device reports no card inserted, and your data is never silently wiped.
ext4 is the robust choice (Linux hosts)
exFAT and FAT32 work, but neither is journaled. ext4 is the most robust option, for two reasons that both matter in the field:
- Power loss. ext4's journal keeps the filesystem consistent even if the device loses power mid-write, and the kernel replays the journal at mount with no host-side repair step.
- Concurrent USB access. The device exposes the card over USB continuously (see Retrieve & view data). On FAT32 and exFAT, a host browsing the card while the device is opening a new session directory can momentarily read inconsistent directory entries. The device is built to tolerate this and keep recording, but ext4 removes the race outright.
If you run long sessions, cut power without stopping cleanly, or routinely copy files over USB mid-session, reformat your cards as ext4.
EGO1's firmware runs Linux kernel 5.10. Current Linux distributions (Debian 12+, Ubuntu 23.04+) ship
e2fsprogs 1.47 or newer, whose mkfs.ext4 enables the orphan_file filesystem feature by default — a
feature that requires kernel 5.15. A card formatted with a plain mkfs.ext4 on such a host will not
mount: the device behaves as if no card were inserted.
Format ext4 cards with the incompatible features disabled:
mkfs.ext4 -F -O ^orphan_file,^metadata_csum_seed /dev/sdX1
If a card formatted this way still isn't recognized, reformat it as exFAT or FAT32 instead.
Inserting and removing
Insert and remove the SD card only while the device is unpowered. After copying recordings to your computer, delete the exported files from the card to free space for the next session — see Retrieve & view data.